xref: /freebsd/contrib/llvm-project/libcxx/include/unordered_map (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_UNORDERED_MAP
11#define _LIBCPP_UNORDERED_MAP
12
13/*
14
15    unordered_map synopsis
16
17#include <initializer_list>
18
19namespace std
20{
21
22template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
23          class Alloc = allocator<pair<const Key, T>>>
24class unordered_map
25{
26public:
27    // types
28    typedef Key                                                        key_type;
29    typedef T                                                          mapped_type;
30    typedef Hash                                                       hasher;
31    typedef Pred                                                       key_equal;
32    typedef Alloc                                                      allocator_type;
33    typedef pair<const key_type, mapped_type>                          value_type;
34    typedef value_type&                                                reference;
35    typedef const value_type&                                          const_reference;
36    typedef typename allocator_traits<allocator_type>::pointer         pointer;
37    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
38    typedef typename allocator_traits<allocator_type>::size_type       size_type;
39    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
40
41    typedef /unspecified/ iterator;
42    typedef /unspecified/ const_iterator;
43    typedef /unspecified/ local_iterator;
44    typedef /unspecified/ const_local_iterator;
45
46    typedef unspecified                             node_type;            // C++17
47    typedef INSERT_RETURN_TYPE<iterator, node_type> insert_return_type;   // C++17
48
49    unordered_map()
50        noexcept(
51            is_nothrow_default_constructible<hasher>::value &&
52            is_nothrow_default_constructible<key_equal>::value &&
53            is_nothrow_default_constructible<allocator_type>::value);
54    explicit unordered_map(size_type n, const hasher& hf = hasher(),
55                           const key_equal& eql = key_equal(),
56                           const allocator_type& a = allocator_type());
57    template <class InputIterator>
58        unordered_map(InputIterator f, InputIterator l,
59                      size_type n = 0, const hasher& hf = hasher(),
60                      const key_equal& eql = key_equal(),
61                      const allocator_type& a = allocator_type());
62    template<container-compatible-range<value_type> R>
63      unordered_map(from_range_t, R&& rg, size_type n = see below,
64        const hasher& hf = hasher(), const key_equal& eql = key_equal(),
65        const allocator_type& a = allocator_type()); // C++23
66
67    explicit unordered_map(const allocator_type&);
68    unordered_map(const unordered_map&);
69    unordered_map(const unordered_map&, const Allocator&);
70    unordered_map(unordered_map&&)
71        noexcept(
72            is_nothrow_move_constructible<hasher>::value &&
73            is_nothrow_move_constructible<key_equal>::value &&
74            is_nothrow_move_constructible<allocator_type>::value);
75    unordered_map(unordered_map&&, const Allocator&);
76    unordered_map(initializer_list<value_type>, size_type n = 0,
77                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
78                  const allocator_type& a = allocator_type());
79    unordered_map(size_type n, const allocator_type& a)
80      : unordered_map(n, hasher(), key_equal(), a) {}  // C++14
81    unordered_map(size_type n, const hasher& hf, const allocator_type& a)
82      : unordered_map(n, hf, key_equal(), a) {}  // C++14
83    template <class InputIterator>
84      unordered_map(InputIterator f, InputIterator l, size_type n, const allocator_type& a)
85      : unordered_map(f, l, n, hasher(), key_equal(), a) {}  // C++14
86    template <class InputIterator>
87      unordered_map(InputIterator f, InputIterator l, size_type n, const hasher& hf,
88        const allocator_type& a)
89      : unordered_map(f, l, n, hf, key_equal(), a) {}  // C++14
90    template<container-compatible-range<value_type> R>
91      unordered_map(from_range_t, R&& rg, size_type n, const allocator_type& a)
92        : unordered_map(from_range, std::forward<R>(rg), n, hasher(), key_equal(), a) { } // C++23
93    template<container-compatible-range<value_type> R>
94      unordered_map(from_range_t, R&& rg, size_type n, const hasher& hf, const allocator_type& a)
95        : unordered_map(from_range, std::forward<R>(rg), n, hf, key_equal(), a) { }       // C++23
96    unordered_map(initializer_list<value_type> il, size_type n, const allocator_type& a)
97      : unordered_map(il, n, hasher(), key_equal(), a) {}  // C++14
98    unordered_map(initializer_list<value_type> il, size_type n, const hasher& hf,
99      const allocator_type& a)
100      : unordered_map(il, n, hf, key_equal(), a) {}  // C++14
101    ~unordered_map();
102    unordered_map& operator=(const unordered_map&);
103    unordered_map& operator=(unordered_map&&)
104        noexcept(
105            allocator_type::propagate_on_container_move_assignment::value &&
106            is_nothrow_move_assignable<allocator_type>::value &&
107            is_nothrow_move_assignable<hasher>::value &&
108            is_nothrow_move_assignable<key_equal>::value);
109    unordered_map& operator=(initializer_list<value_type>);
110
111    allocator_type get_allocator() const noexcept;
112
113    bool      empty() const noexcept;
114    size_type size() const noexcept;
115    size_type max_size() const noexcept;
116
117    iterator       begin() noexcept;
118    iterator       end() noexcept;
119    const_iterator begin()  const noexcept;
120    const_iterator end()    const noexcept;
121    const_iterator cbegin() const noexcept;
122    const_iterator cend()   const noexcept;
123
124    template <class... Args>
125        pair<iterator, bool> emplace(Args&&... args);
126    template <class... Args>
127        iterator emplace_hint(const_iterator position, Args&&... args);
128    pair<iterator, bool> insert(const value_type& obj);
129    template <class P>
130        pair<iterator, bool> insert(P&& obj);
131    iterator insert(const_iterator hint, const value_type& obj);
132    template <class P>
133        iterator insert(const_iterator hint, P&& obj);
134    template <class InputIterator>
135        void insert(InputIterator first, InputIterator last);
136    template<container-compatible-range<value_type> R>
137      void insert_range(R&& rg);                                                      // C++23
138    void insert(initializer_list<value_type>);
139
140    node_type extract(const_iterator position);                                       // C++17
141    node_type extract(const key_type& x);                                             // C++17
142    insert_return_type insert(node_type&& nh);                                        // C++17
143    iterator           insert(const_iterator hint, node_type&& nh);                   // C++17
144
145    template <class... Args>
146        pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);          // C++17
147    template <class... Args>
148        pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);               // C++17
149    template <class... Args>
150        iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); // C++17
151    template <class... Args>
152        iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);      // C++17
153    template <class M>
154        pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj);            // C++17
155    template <class M>
156        pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj);                 // C++17
157    template <class M>
158        iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj);   // C++17
159    template <class M>
160        iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj);        // C++17
161
162    iterator erase(const_iterator position);
163    iterator erase(iterator position);  // C++14
164    size_type erase(const key_type& k);
165    iterator erase(const_iterator first, const_iterator last);
166    void clear() noexcept;
167
168    template<class H2, class P2>
169      void merge(unordered_map<Key, T, H2, P2, Allocator>& source);         // C++17
170    template<class H2, class P2>
171      void merge(unordered_map<Key, T, H2, P2, Allocator>&& source);        // C++17
172    template<class H2, class P2>
173      void merge(unordered_multimap<Key, T, H2, P2, Allocator>& source);    // C++17
174    template<class H2, class P2>
175      void merge(unordered_multimap<Key, T, H2, P2, Allocator>&& source);   // C++17
176
177    void swap(unordered_map&)
178        noexcept(
179            (!allocator_type::propagate_on_container_swap::value ||
180             __is_nothrow_swappable<allocator_type>::value) &&
181            __is_nothrow_swappable<hasher>::value &&
182            __is_nothrow_swappable<key_equal>::value);
183
184    hasher hash_function() const;
185    key_equal key_eq() const;
186
187    iterator       find(const key_type& k);
188    const_iterator find(const key_type& k) const;
189    template<typename K>
190        iterator find(const K& x);              // C++20
191    template<typename K>
192        const_iterator find(const K& x) const;  // C++20
193    size_type count(const key_type& k) const;
194    template<typename K>
195        size_type count(const K& k) const; // C++20
196    bool contains(const key_type& k) const; // C++20
197    template<typename K>
198        bool contains(const K& k) const; // C++20
199    pair<iterator, iterator>             equal_range(const key_type& k);
200    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
201    template<typename K>
202        pair<iterator, iterator>             equal_range(const K& k); // C++20
203    template<typename K>
204        pair<const_iterator, const_iterator> equal_range(const K& k) const; // C++20
205
206    mapped_type& operator[](const key_type& k);
207    mapped_type& operator[](key_type&& k);
208
209    mapped_type&       at(const key_type& k);
210    const mapped_type& at(const key_type& k) const;
211
212    size_type bucket_count() const noexcept;
213    size_type max_bucket_count() const noexcept;
214
215    size_type bucket_size(size_type n) const;
216    size_type bucket(const key_type& k) const;
217
218    local_iterator       begin(size_type n);
219    local_iterator       end(size_type n);
220    const_local_iterator begin(size_type n) const;
221    const_local_iterator end(size_type n) const;
222    const_local_iterator cbegin(size_type n) const;
223    const_local_iterator cend(size_type n) const;
224
225    float load_factor() const noexcept;
226    float max_load_factor() const noexcept;
227    void max_load_factor(float z);
228    void rehash(size_type n);
229    void reserve(size_type n);
230};
231
232template<class InputIterator,
233    class Hash = hash<iter_key_t<InputIterator>>, class Pred = equal_to<iter_key_t<InputIterator>>,
234    class Allocator = allocator<iter_to_alloc_t<InputIterator>>>
235unordered_map(InputIterator, InputIterator, typename see below::size_type = see below,
236    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
237  -> unordered_map<iter_key_t<InputIterator>, iter_value_t<InputIterator>, Hash, Pred,
238    Allocator>; // C++17
239
240template<ranges::input_range R, class Hash = hash<range-key-type<R>>,
241         class Pred = equal_to<range-key-type<R>>,
242         class Allocator = allocator<range-to-alloc-type<R>>>
243  unordered_map(from_range_t, R&&, typename see below::size_type = see below,
244                Hash = Hash(), Pred = Pred(), Allocator = Allocator())
245    -> unordered_map<range-key-type<R>, range-mapped-type<R>, Hash, Pred, Allocator>; // C++23
246
247template<class Key, class T, class Hash = hash<Key>,
248    class Pred = equal_to<Key>, class Allocator = allocator<pair<const Key, T>>>
249unordered_map(initializer_list<pair<const Key, T>>, typename see below::size_type = see below,
250    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
251  -> unordered_map<Key, T, Hash, Pred, Allocator>; // C++17
252
253template<class InputIterator, class Allocator>
254unordered_map(InputIterator, InputIterator, typename see below::size_type, Allocator)
255  -> unordered_map<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
256        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
257
258template<class InputIterator, class Allocator>
259unordered_map(InputIterator, InputIterator, Allocator)
260  -> unordered_map<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
261        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
262
263template<class InputIterator, class Hash, class Allocator>
264unordered_map(InputIterator, InputIterator, typename see below::size_type, Hash, Allocator)
265  -> unordered_map<iter_key_t<InputIterator>, iter_val_t<InputIterator>, Hash,
266          equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
267
268template<ranges::input_range R, class Allocator>
269  unordered_map(from_range_t, R&&, typename see below::size_type, Allocator)
270    -> unordered_map<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
271                      equal_to<range-key-type<R>>, Allocator>;   // C++23
272
273template<ranges::input_range R, class Allocator>
274  unordered_map(from_range_t, R&&, Allocator)
275    -> unordered_map<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
276                      equal_to<range-key-type<R>>, Allocator>;   // C++23
277
278template<ranges::input_range R, class Hash, class Allocator>
279  unordered_map(from_range_t, R&&, typename see below::size_type, Hash, Allocator)
280    -> unordered_map<range-key-type<R>, range-mapped-type<R>, Hash,
281                      equal_to<range-key-type<R>>, Allocator>;   // C++23
282
283template<class Key, class T, typename Allocator>
284unordered_map(initializer_list<pair<const Key, T>>, typename see below::size_type, Allocator)
285  -> unordered_map<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
286
287template<class Key, class T, typename Allocator>
288unordered_map(initializer_list<pair<const Key, T>>, Allocator)
289  -> unordered_map<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
290
291template<class Key, class T, class Hash, class Allocator>
292unordered_map(initializer_list<pair<const Key, T>>, typename see below::size_type, Hash, Allocator)
293  -> unordered_map<Key, T, Hash, equal_to<Key>, Allocator>; // C++17
294
295template <class Key, class T, class Hash, class Pred, class Alloc>
296    void swap(unordered_map<Key, T, Hash, Pred, Alloc>& x,
297              unordered_map<Key, T, Hash, Pred, Alloc>& y)
298              noexcept(noexcept(x.swap(y)));
299
300template <class Key, class T, class Hash, class Pred, class Alloc>
301    bool
302    operator==(const unordered_map<Key, T, Hash, Pred, Alloc>& x,
303               const unordered_map<Key, T, Hash, Pred, Alloc>& y);
304
305template <class Key, class T, class Hash, class Pred, class Alloc>
306    bool
307    operator!=(const unordered_map<Key, T, Hash, Pred, Alloc>& x,
308               const unordered_map<Key, T, Hash, Pred, Alloc>& y); // Removed in C++20
309
310template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
311          class Alloc = allocator<pair<const Key, T>>>
312class unordered_multimap
313{
314public:
315    // types
316    typedef Key                                                        key_type;
317    typedef T                                                          mapped_type;
318    typedef Hash                                                       hasher;
319    typedef Pred                                                       key_equal;
320    typedef Alloc                                                      allocator_type;
321    typedef pair<const key_type, mapped_type>                          value_type;
322    typedef value_type&                                                reference;
323    typedef const value_type&                                          const_reference;
324    typedef typename allocator_traits<allocator_type>::pointer         pointer;
325    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
326    typedef typename allocator_traits<allocator_type>::size_type       size_type;
327    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
328
329    typedef /unspecified/ iterator;
330    typedef /unspecified/ const_iterator;
331    typedef /unspecified/ local_iterator;
332    typedef /unspecified/ const_local_iterator;
333
334    typedef unspecified node_type;    // C++17
335
336    unordered_multimap()
337        noexcept(
338            is_nothrow_default_constructible<hasher>::value &&
339            is_nothrow_default_constructible<key_equal>::value &&
340            is_nothrow_default_constructible<allocator_type>::value);
341    explicit unordered_multimap(size_type n, const hasher& hf = hasher(),
342                           const key_equal& eql = key_equal(),
343                           const allocator_type& a = allocator_type());
344    template <class InputIterator>
345        unordered_multimap(InputIterator f, InputIterator l,
346                      size_type n = 0, const hasher& hf = hasher(),
347                      const key_equal& eql = key_equal(),
348                      const allocator_type& a = allocator_type());
349    template<container-compatible-range<value_type> R>
350      unordered_multimap(from_range_t, R&& rg, size_type n = see below,
351        const hasher& hf = hasher(), const key_equal& eql = key_equal(),
352        const allocator_type& a = allocator_type()); // C++23
353    explicit unordered_multimap(const allocator_type&);
354    unordered_multimap(const unordered_multimap&);
355    unordered_multimap(const unordered_multimap&, const Allocator&);
356    unordered_multimap(unordered_multimap&&)
357        noexcept(
358            is_nothrow_move_constructible<hasher>::value &&
359            is_nothrow_move_constructible<key_equal>::value &&
360            is_nothrow_move_constructible<allocator_type>::value);
361    unordered_multimap(unordered_multimap&&, const Allocator&);
362    unordered_multimap(initializer_list<value_type>, size_type n = 0,
363                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
364                  const allocator_type& a = allocator_type());
365    unordered_multimap(size_type n, const allocator_type& a)
366      : unordered_multimap(n, hasher(), key_equal(), a) {}  // C++14
367    unordered_multimap(size_type n, const hasher& hf, const allocator_type& a)
368      : unordered_multimap(n, hf, key_equal(), a) {}  // C++14
369    template <class InputIterator>
370      unordered_multimap(InputIterator f, InputIterator l, size_type n, const allocator_type& a)
371      : unordered_multimap(f, l, n, hasher(), key_equal(), a) {}  // C++14
372    template <class InputIterator>
373      unordered_multimap(InputIterator f, InputIterator l, size_type n, const hasher& hf,
374        const allocator_type& a)
375      : unordered_multimap(f, l, n, hf, key_equal(), a) {}  // C++14
376    template<container-compatible-range<value_type> R>
377      unordered_multimap(from_range_t, R&& rg, size_type n, const allocator_type& a)
378        : unordered_multimap(from_range, std::forward<R>(rg), n, hasher(), key_equal(), a) { } // C++23
379    template<container-compatible-range<value_type> R>
380      unordered_multimap(from_range_t, R&& rg, size_type n, const hasher& hf, const allocator_type& a)
381        : unordered_multimap(from_range, std::forward<R>(rg), n, hf, key_equal(), a) { }       // C++23
382    unordered_multimap(initializer_list<value_type> il, size_type n, const allocator_type& a)
383      : unordered_multimap(il, n, hasher(), key_equal(), a) {}  // C++14
384    unordered_multimap(initializer_list<value_type> il, size_type n, const hasher& hf,
385      const allocator_type& a)
386      : unordered_multimap(il, n, hf, key_equal(), a) {}  // C++14
387    ~unordered_multimap();
388    unordered_multimap& operator=(const unordered_multimap&);
389    unordered_multimap& operator=(unordered_multimap&&)
390        noexcept(
391            allocator_type::propagate_on_container_move_assignment::value &&
392            is_nothrow_move_assignable<allocator_type>::value &&
393            is_nothrow_move_assignable<hasher>::value &&
394            is_nothrow_move_assignable<key_equal>::value);
395    unordered_multimap& operator=(initializer_list<value_type>);
396
397    allocator_type get_allocator() const noexcept;
398
399    bool      empty() const noexcept;
400    size_type size() const noexcept;
401    size_type max_size() const noexcept;
402
403    iterator       begin() noexcept;
404    iterator       end() noexcept;
405    const_iterator begin()  const noexcept;
406    const_iterator end()    const noexcept;
407    const_iterator cbegin() const noexcept;
408    const_iterator cend()   const noexcept;
409
410    template <class... Args>
411        iterator emplace(Args&&... args);
412    template <class... Args>
413        iterator emplace_hint(const_iterator position, Args&&... args);
414    iterator insert(const value_type& obj);
415    template <class P>
416        iterator insert(P&& obj);
417    iterator insert(const_iterator hint, const value_type& obj);
418    template <class P>
419        iterator insert(const_iterator hint, P&& obj);
420    template <class InputIterator>
421        void insert(InputIterator first, InputIterator last);
422    template<container-compatible-range<value_type> R>
423      void insert_range(R&& rg);                               // C++23
424    void insert(initializer_list<value_type>);
425
426    node_type extract(const_iterator position);                // C++17
427    node_type extract(const key_type& x);                      // C++17
428    iterator insert(node_type&& nh);                           // C++17
429    iterator insert(const_iterator hint, node_type&& nh);      // C++17
430
431    iterator erase(const_iterator position);
432    iterator erase(iterator position);  // C++14
433    size_type erase(const key_type& k);
434    iterator erase(const_iterator first, const_iterator last);
435    void clear() noexcept;
436
437    template<class H2, class P2>
438      void merge(unordered_multimap<Key, T, H2, P2, Allocator>& source);    // C++17
439    template<class H2, class P2>
440      void merge(unordered_multimap<Key, T, H2, P2, Allocator>&& source);   // C++17
441    template<class H2, class P2>
442      void merge(unordered_map<Key, T, H2, P2, Allocator>& source);         // C++17
443    template<class H2, class P2>
444      void merge(unordered_map<Key, T, H2, P2, Allocator>&& source);        // C++17
445
446    void swap(unordered_multimap&)
447        noexcept(
448            (!allocator_type::propagate_on_container_swap::value ||
449             __is_nothrow_swappable<allocator_type>::value) &&
450            __is_nothrow_swappable<hasher>::value &&
451            __is_nothrow_swappable<key_equal>::value);
452
453    hasher hash_function() const;
454    key_equal key_eq() const;
455
456    iterator       find(const key_type& k);
457    const_iterator find(const key_type& k) const;
458    template<typename K>
459        iterator find(const K& x);              // C++20
460    template<typename K>
461        const_iterator find(const K& x) const;  // C++20
462    size_type count(const key_type& k) const;
463    template<typename K>
464        size_type count(const K& k) const; // C++20
465    bool contains(const key_type& k) const; // C++20
466    template<typename K>
467        bool contains(const K& k) const; // C++20
468    pair<iterator, iterator>             equal_range(const key_type& k);
469    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
470    template<typename K>
471        pair<iterator, iterator>             equal_range(const K& k); // C++20
472    template<typename K>
473        pair<const_iterator, const_iterator> equal_range(const K& k) const; // C++20
474
475    size_type bucket_count() const noexcept;
476    size_type max_bucket_count() const noexcept;
477
478    size_type bucket_size(size_type n) const;
479    size_type bucket(const key_type& k) const;
480
481    local_iterator       begin(size_type n);
482    local_iterator       end(size_type n);
483    const_local_iterator begin(size_type n) const;
484    const_local_iterator end(size_type n) const;
485    const_local_iterator cbegin(size_type n) const;
486    const_local_iterator cend(size_type n) const;
487
488    float load_factor() const noexcept;
489    float max_load_factor() const noexcept;
490    void max_load_factor(float z);
491    void rehash(size_type n);
492    void reserve(size_type n);
493};
494
495template<class InputIterator,
496    class Hash = hash<iter_key_t<InputIterator>>, class Pred = equal_to<iter_key_t<InputIterator>>,
497    class Allocator = allocator<iter_to_alloc_t<InputIterator>>>
498unordered_multimap(InputIterator, InputIterator, typename see below::size_type = see below,
499    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
500  -> unordered_multimap<iter_key_t<InputIterator>, iter_value_t<InputIterator>, Hash, Pred,
501    Allocator>; // C++17
502
503template<ranges::input_range R, class Hash = hash<range-key-type<R>>,
504         class Pred = equal_to<range-key-type<R>>,
505         class Allocator = allocator<range-to-alloc-type<R>>>
506  unordered_multimap(from_range_t, R&&, typename see below::size_type = see below,
507                Hash = Hash(), Pred = Pred(), Allocator = Allocator())
508    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, Hash, Pred, Allocator>; // C++23
509
510template<class Key, class T, class Hash = hash<Key>,
511    class Pred = equal_to<Key>, class Allocator = allocator<pair<const Key, T>>>
512unordered_multimap(initializer_list<pair<const Key, T>>, typename see below::size_type = see below,
513    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
514  -> unordered_multimap<Key, T, Hash, Pred, Allocator>; // C++17
515
516template<class InputIterator, class Allocator>
517unordered_multimap(InputIterator, InputIterator, typename see below::size_type, Allocator)
518  -> unordered_multimap<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
519        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
520
521template<class InputIterator, class Allocator>
522unordered_multimap(InputIterator, InputIterator, Allocator)
523  -> unordered_multimap<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
524        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
525
526template<class InputIterator, class Hash, class Allocator>
527unordered_multimap(InputIterator, InputIterator, typename see below::size_type, Hash, Allocator)
528  -> unordered_multimap<iter_key_t<InputIterator>, iter_val_t<InputIterator>, Hash,
529          equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
530
531template<ranges::input_range R, class Allocator>
532  unordered_multimap(from_range_t, R&&, typename see below::size_type, Allocator)
533    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
534                      equal_to<range-key-type<R>>, Allocator>;   // C++23
535
536template<ranges::input_range R, class Allocator>
537  unordered_multimap(from_range_t, R&&, Allocator)
538    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
539                      equal_to<range-key-type<R>>, Allocator>;   // C++23
540
541template<ranges::input_range R, class Hash, class Allocator>
542  unordered_multimap(from_range_t, R&&, typename see below::size_type, Hash, Allocator)
543    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, Hash,
544                      equal_to<range-key-type<R>>, Allocator>;   // C++23
545
546template<class Key, class T, typename Allocator>
547unordered_multimap(initializer_list<pair<const Key, T>>, typename see below::size_type, Allocator)
548  -> unordered_multimap<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
549
550template<class Key, class T, typename Allocator>
551unordered_multimap(initializer_list<pair<const Key, T>>, Allocator)
552  -> unordered_multimap<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
553
554template<class Key, class T, class Hash, class Allocator>
555unordered_multimap(initializer_list<pair<const Key, T>>, typename see below::size_type, Hash,
556    Allocator)
557  -> unordered_multimap<Key, T, Hash, equal_to<Key>, Allocator>; // C++17
558
559template <class Key, class T, class Hash, class Pred, class Alloc>
560    void swap(unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
561              unordered_multimap<Key, T, Hash, Pred, Alloc>& y)
562              noexcept(noexcept(x.swap(y)));
563
564template <class K, class T, class H, class P, class A, class Predicate>
565    typename unordered_map<K, T, H, P, A>::size_type
566    erase_if(unordered_map<K, T, H, P, A>& c, Predicate pred);       // C++20
567
568template <class K, class T, class H, class P, class A, class Predicate>
569    typename unordered_multimap<K, T, H, P, A>::size_type
570    erase_if(unordered_multimap<K, T, H, P, A>& c, Predicate pred);  // C++20
571
572template <class Key, class T, class Hash, class Pred, class Alloc>
573    bool
574    operator==(const unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
575               const unordered_multimap<Key, T, Hash, Pred, Alloc>& y);
576
577template <class Key, class T, class Hash, class Pred, class Alloc>
578    bool
579    operator!=(const unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
580               const unordered_multimap<Key, T, Hash, Pred, Alloc>& y); // Removed in C++20
581
582}  // std
583
584*/
585
586#include <__algorithm/is_permutation.h>
587#include <__assert> // all public C++ headers provide the assertion handler
588#include <__availability>
589#include <__config>
590#include <__functional/is_transparent.h>
591#include <__functional/operations.h>
592#include <__hash_table>
593#include <__iterator/distance.h>
594#include <__iterator/erase_if_container.h>
595#include <__iterator/iterator_traits.h>
596#include <__iterator/ranges_iterator_traits.h>
597#include <__memory/addressof.h>
598#include <__memory/allocator.h>
599#include <__memory_resource/polymorphic_allocator.h>
600#include <__node_handle>
601#include <__ranges/concepts.h>
602#include <__ranges/container_compatible_range.h>
603#include <__ranges/from_range.h>
604#include <__type_traits/is_allocator.h>
605#include <__type_traits/type_identity.h>
606#include <__utility/forward.h>
607#include <stdexcept>
608#include <tuple>
609#include <version>
610
611// standard-mandated includes
612
613// [iterator.range]
614#include <__iterator/access.h>
615#include <__iterator/data.h>
616#include <__iterator/empty.h>
617#include <__iterator/reverse_access.h>
618#include <__iterator/size.h>
619
620// [unord.map.syn]
621#include <compare>
622#include <initializer_list>
623
624#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
625#  pragma GCC system_header
626#endif
627
628_LIBCPP_BEGIN_NAMESPACE_STD
629
630template <class _Key,
631          class _Cp,
632          class _Hash,
633          class _Pred,
634          bool = is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value>
635class __unordered_map_hasher : private _Hash {
636public:
637  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher() _NOEXCEPT_(is_nothrow_default_constructible<_Hash>::value) : _Hash() {}
638  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher(const _Hash& __h) _NOEXCEPT_(is_nothrow_copy_constructible<_Hash>::value)
639      : _Hash(__h) {}
640  _LIBCPP_HIDE_FROM_ABI const _Hash& hash_function() const _NOEXCEPT { return *this; }
641  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Cp& __x) const {
642    return static_cast<const _Hash&>(*this)(__x.__get_value().first);
643  }
644  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Key& __x) const { return static_cast<const _Hash&>(*this)(__x); }
645#if _LIBCPP_STD_VER >= 20
646  template <typename _K2>
647  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _K2& __x) const {
648    return static_cast<const _Hash&>(*this)(__x);
649  }
650#endif
651  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_hasher& __y) _NOEXCEPT_(__is_nothrow_swappable<_Hash>::value) {
652    using std::swap;
653    swap(static_cast<_Hash&>(*this), static_cast<_Hash&>(__y));
654  }
655};
656
657template <class _Key, class _Cp, class _Hash, class _Pred>
658class __unordered_map_hasher<_Key, _Cp, _Hash, _Pred, false> {
659  _Hash __hash_;
660
661public:
662  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher() _NOEXCEPT_(is_nothrow_default_constructible<_Hash>::value)
663      : __hash_() {}
664  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher(const _Hash& __h) _NOEXCEPT_(is_nothrow_copy_constructible<_Hash>::value)
665      : __hash_(__h) {}
666  _LIBCPP_HIDE_FROM_ABI const _Hash& hash_function() const _NOEXCEPT { return __hash_; }
667  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Cp& __x) const { return __hash_(__x.__get_value().first); }
668  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Key& __x) const { return __hash_(__x); }
669#if _LIBCPP_STD_VER >= 20
670  template <typename _K2>
671  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _K2& __x) const {
672    return __hash_(__x);
673  }
674#endif
675  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_hasher& __y) _NOEXCEPT_(__is_nothrow_swappable<_Hash>::value) {
676    using std::swap;
677    swap(__hash_, __y.__hash_);
678  }
679};
680
681template <class _Key, class _Cp, class _Hash, class _Pred, bool __b>
682inline _LIBCPP_HIDE_FROM_ABI void
683swap(__unordered_map_hasher<_Key, _Cp, _Hash, _Pred, __b>& __x,
684     __unordered_map_hasher<_Key, _Cp, _Hash, _Pred, __b>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
685  __x.swap(__y);
686}
687
688template <class _Key,
689          class _Cp,
690          class _Pred,
691          class _Hash,
692          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value>
693class __unordered_map_equal : private _Pred {
694public:
695  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal() _NOEXCEPT_(is_nothrow_default_constructible<_Pred>::value) : _Pred() {}
696  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal(const _Pred& __p) _NOEXCEPT_(is_nothrow_copy_constructible<_Pred>::value)
697      : _Pred(__p) {}
698  _LIBCPP_HIDE_FROM_ABI const _Pred& key_eq() const _NOEXCEPT { return *this; }
699  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Cp& __y) const {
700    return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y.__get_value().first);
701  }
702  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Key& __y) const {
703    return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y);
704  }
705  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _Cp& __y) const {
706    return static_cast<const _Pred&>(*this)(__x, __y.__get_value().first);
707  }
708#if _LIBCPP_STD_VER >= 20
709  template <typename _K2>
710  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _K2& __y) const {
711    return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y);
712  }
713  template <typename _K2>
714  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Cp& __y) const {
715    return static_cast<const _Pred&>(*this)(__x, __y.__get_value().first);
716  }
717  template <typename _K2>
718  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _K2& __y) const {
719    return static_cast<const _Pred&>(*this)(__x, __y);
720  }
721  template <typename _K2>
722  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Key& __y) const {
723    return static_cast<const _Pred&>(*this)(__x, __y);
724  }
725#endif
726  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_equal& __y) _NOEXCEPT_(__is_nothrow_swappable<_Pred>::value) {
727    using std::swap;
728    swap(static_cast<_Pred&>(*this), static_cast<_Pred&>(__y));
729  }
730};
731
732template <class _Key, class _Cp, class _Pred, class _Hash>
733class __unordered_map_equal<_Key, _Cp, _Pred, _Hash, false> {
734  _Pred __pred_;
735
736public:
737  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal() _NOEXCEPT_(is_nothrow_default_constructible<_Pred>::value)
738      : __pred_() {}
739  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal(const _Pred& __p) _NOEXCEPT_(is_nothrow_copy_constructible<_Pred>::value)
740      : __pred_(__p) {}
741  _LIBCPP_HIDE_FROM_ABI const _Pred& key_eq() const _NOEXCEPT { return __pred_; }
742  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Cp& __y) const {
743    return __pred_(__x.__get_value().first, __y.__get_value().first);
744  }
745  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Key& __y) const {
746    return __pred_(__x.__get_value().first, __y);
747  }
748  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _Cp& __y) const {
749    return __pred_(__x, __y.__get_value().first);
750  }
751#if _LIBCPP_STD_VER >= 20
752  template <typename _K2>
753  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _K2& __y) const {
754    return __pred_(__x.__get_value().first, __y);
755  }
756  template <typename _K2>
757  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Cp& __y) const {
758    return __pred_(__x, __y.__get_value().first);
759  }
760  template <typename _K2>
761  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _K2& __y) const {
762    return __pred_(__x, __y);
763  }
764  template <typename _K2>
765  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Key& __y) const {
766    return __pred_(__x, __y);
767  }
768#endif
769  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_equal& __y) _NOEXCEPT_(__is_nothrow_swappable<_Pred>::value) {
770    using std::swap;
771    swap(__pred_, __y.__pred_);
772  }
773};
774
775template <class _Key, class _Cp, class _Pred, class _Hash, bool __b>
776inline _LIBCPP_HIDE_FROM_ABI void
777swap(__unordered_map_equal<_Key, _Cp, _Pred, _Hash, __b>& __x, __unordered_map_equal<_Key, _Cp, _Pred, _Hash, __b>& __y)
778    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
779  __x.swap(__y);
780}
781
782template <class _Alloc>
783class __hash_map_node_destructor {
784  typedef _Alloc allocator_type;
785  typedef allocator_traits<allocator_type> __alloc_traits;
786
787public:
788  typedef typename __alloc_traits::pointer pointer;
789
790private:
791  allocator_type& __na_;
792
793  __hash_map_node_destructor& operator=(const __hash_map_node_destructor&);
794
795public:
796  bool __first_constructed;
797  bool __second_constructed;
798
799  _LIBCPP_HIDE_FROM_ABI explicit __hash_map_node_destructor(allocator_type& __na) _NOEXCEPT
800      : __na_(__na),
801        __first_constructed(false),
802        __second_constructed(false) {}
803
804#ifndef _LIBCPP_CXX03_LANG
805  _LIBCPP_HIDE_FROM_ABI __hash_map_node_destructor(__hash_node_destructor<allocator_type>&& __x) _NOEXCEPT
806      : __na_(__x.__na_),
807        __first_constructed(__x.__value_constructed),
808        __second_constructed(__x.__value_constructed) {
809    __x.__value_constructed = false;
810  }
811#else  // _LIBCPP_CXX03_LANG
812  _LIBCPP_HIDE_FROM_ABI __hash_map_node_destructor(const __hash_node_destructor<allocator_type>& __x)
813      : __na_(__x.__na_), __first_constructed(__x.__value_constructed), __second_constructed(__x.__value_constructed) {
814    const_cast<bool&>(__x.__value_constructed) = false;
815  }
816#endif // _LIBCPP_CXX03_LANG
817
818  _LIBCPP_HIDE_FROM_ABI void operator()(pointer __p) _NOEXCEPT {
819    if (__second_constructed)
820      __alloc_traits::destroy(__na_, std::addressof(__p->__get_value().__get_value().second));
821    if (__first_constructed)
822      __alloc_traits::destroy(__na_, std::addressof(__p->__get_value().__get_value().first));
823    if (__p)
824      __alloc_traits::deallocate(__na_, __p, 1);
825  }
826};
827
828#ifndef _LIBCPP_CXX03_LANG
829template <class _Key, class _Tp>
830struct _LIBCPP_STANDALONE_DEBUG __hash_value_type {
831  typedef _Key key_type;
832  typedef _Tp mapped_type;
833  typedef pair<const key_type, mapped_type> value_type;
834  typedef pair<key_type&, mapped_type&> __nc_ref_pair_type;
835  typedef pair<key_type&&, mapped_type&&> __nc_rref_pair_type;
836
837private:
838  value_type __cc_;
839
840public:
841  _LIBCPP_HIDE_FROM_ABI value_type& __get_value() {
842#  if _LIBCPP_STD_VER >= 17
843    return *std::launder(std::addressof(__cc_));
844#  else
845    return __cc_;
846#  endif
847  }
848
849  _LIBCPP_HIDE_FROM_ABI const value_type& __get_value() const {
850#  if _LIBCPP_STD_VER >= 17
851    return *std::launder(std::addressof(__cc_));
852#  else
853    return __cc_;
854#  endif
855  }
856
857  _LIBCPP_HIDE_FROM_ABI __nc_ref_pair_type __ref() {
858    value_type& __v = __get_value();
859    return __nc_ref_pair_type(const_cast<key_type&>(__v.first), __v.second);
860  }
861
862  _LIBCPP_HIDE_FROM_ABI __nc_rref_pair_type __move() {
863    value_type& __v = __get_value();
864    return __nc_rref_pair_type(std::move(const_cast<key_type&>(__v.first)), std::move(__v.second));
865  }
866
867  _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(const __hash_value_type& __v) {
868    __ref() = __v.__get_value();
869    return *this;
870  }
871
872  _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(__hash_value_type&& __v) {
873    __ref() = __v.__move();
874    return *this;
875  }
876
877  template <class _ValueTp, class = __enable_if_t<__is_same_uncvref<_ValueTp, value_type>::value> >
878  _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(_ValueTp&& __v) {
879    __ref() = std::forward<_ValueTp>(__v);
880    return *this;
881  }
882
883private:
884  __hash_value_type(const __hash_value_type& __v) = delete;
885  __hash_value_type(__hash_value_type&& __v)      = delete;
886  template <class... _Args>
887  explicit __hash_value_type(_Args&&... __args) = delete;
888
889  ~__hash_value_type() = delete;
890};
891
892#else
893
894template <class _Key, class _Tp>
895struct __hash_value_type {
896  typedef _Key key_type;
897  typedef _Tp mapped_type;
898  typedef pair<const key_type, mapped_type> value_type;
899
900private:
901  value_type __cc_;
902
903public:
904  _LIBCPP_HIDE_FROM_ABI value_type& __get_value() { return __cc_; }
905  _LIBCPP_HIDE_FROM_ABI const value_type& __get_value() const { return __cc_; }
906
907private:
908  ~__hash_value_type();
909};
910
911#endif
912
913template <class _HashIterator>
914class _LIBCPP_TEMPLATE_VIS __hash_map_iterator {
915  _HashIterator __i_;
916
917  typedef __hash_node_types_from_iterator<_HashIterator> _NodeTypes;
918
919public:
920  typedef forward_iterator_tag iterator_category;
921  typedef typename _NodeTypes::__map_value_type value_type;
922  typedef typename _NodeTypes::difference_type difference_type;
923  typedef value_type& reference;
924  typedef typename _NodeTypes::__map_value_type_pointer pointer;
925
926  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator() _NOEXCEPT {}
927
928  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator(_HashIterator __i) _NOEXCEPT : __i_(__i) {}
929
930  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return __i_->__get_value(); }
931  _LIBCPP_HIDE_FROM_ABI pointer operator->() const { return pointer_traits<pointer>::pointer_to(__i_->__get_value()); }
932
933  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator& operator++() {
934    ++__i_;
935    return *this;
936  }
937  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator operator++(int) {
938    __hash_map_iterator __t(*this);
939    ++(*this);
940    return __t;
941  }
942
943  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const __hash_map_iterator& __x, const __hash_map_iterator& __y) {
944    return __x.__i_ == __y.__i_;
945  }
946#if _LIBCPP_STD_VER <= 17
947  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const __hash_map_iterator& __x, const __hash_map_iterator& __y) {
948    return __x.__i_ != __y.__i_;
949  }
950#endif
951
952  template <class, class, class, class, class>
953  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
954  template <class, class, class, class, class>
955  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
956  template <class>
957  friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
958  template <class>
959  friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
960  template <class>
961  friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
962};
963
964template <class _HashIterator>
965class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator {
966  _HashIterator __i_;
967
968  typedef __hash_node_types_from_iterator<_HashIterator> _NodeTypes;
969
970public:
971  typedef forward_iterator_tag iterator_category;
972  typedef typename _NodeTypes::__map_value_type value_type;
973  typedef typename _NodeTypes::difference_type difference_type;
974  typedef const value_type& reference;
975  typedef typename _NodeTypes::__const_map_value_type_pointer pointer;
976
977  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator() _NOEXCEPT {}
978
979  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator(_HashIterator __i) _NOEXCEPT : __i_(__i) {}
980  _LIBCPP_HIDE_FROM_ABI
981  __hash_map_const_iterator(__hash_map_iterator<typename _HashIterator::__non_const_iterator> __i) _NOEXCEPT
982      : __i_(__i.__i_) {}
983
984  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return __i_->__get_value(); }
985  _LIBCPP_HIDE_FROM_ABI pointer operator->() const { return pointer_traits<pointer>::pointer_to(__i_->__get_value()); }
986
987  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator& operator++() {
988    ++__i_;
989    return *this;
990  }
991  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator operator++(int) {
992    __hash_map_const_iterator __t(*this);
993    ++(*this);
994    return __t;
995  }
996
997  friend _LIBCPP_HIDE_FROM_ABI bool
998  operator==(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y) {
999    return __x.__i_ == __y.__i_;
1000  }
1001#if _LIBCPP_STD_VER <= 17
1002  friend _LIBCPP_HIDE_FROM_ABI bool
1003  operator!=(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y) {
1004    return __x.__i_ != __y.__i_;
1005  }
1006#endif
1007
1008  template <class, class, class, class, class>
1009  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1010  template <class, class, class, class, class>
1011  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1012  template <class>
1013  friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
1014  template <class>
1015  friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
1016};
1017
1018template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1019class unordered_multimap;
1020
1021template <class _Key,
1022          class _Tp,
1023          class _Hash  = hash<_Key>,
1024          class _Pred  = equal_to<_Key>,
1025          class _Alloc = allocator<pair<const _Key, _Tp> > >
1026class _LIBCPP_TEMPLATE_VIS unordered_map {
1027public:
1028  // types
1029  typedef _Key key_type;
1030  typedef _Tp mapped_type;
1031  typedef __type_identity_t<_Hash> hasher;
1032  typedef __type_identity_t<_Pred> key_equal;
1033  typedef __type_identity_t<_Alloc> allocator_type;
1034  typedef pair<const key_type, mapped_type> value_type;
1035  typedef value_type& reference;
1036  typedef const value_type& const_reference;
1037  static_assert((is_same<value_type, typename allocator_type::value_type>::value),
1038                "Allocator::value_type must be same type as value_type");
1039
1040private:
1041  typedef __hash_value_type<key_type, mapped_type> __value_type;
1042  typedef __unordered_map_hasher<key_type, __value_type, hasher, key_equal> __hasher;
1043  typedef __unordered_map_equal<key_type, __value_type, key_equal, hasher> __key_equal;
1044  typedef __rebind_alloc<allocator_traits<allocator_type>, __value_type> __allocator_type;
1045
1046  typedef __hash_table<__value_type, __hasher, __key_equal, __allocator_type> __table;
1047
1048  __table __table_;
1049
1050  typedef typename __table::_NodeTypes _NodeTypes;
1051  typedef typename __table::__node_pointer __node_pointer;
1052  typedef typename __table::__node_const_pointer __node_const_pointer;
1053  typedef typename __table::__node_traits __node_traits;
1054  typedef typename __table::__node_allocator __node_allocator;
1055  typedef typename __table::__node __node;
1056  typedef __hash_map_node_destructor<__node_allocator> _Dp;
1057  typedef unique_ptr<__node, _Dp> __node_holder;
1058  typedef allocator_traits<allocator_type> __alloc_traits;
1059
1060  static_assert(is_same<allocator_type, __rebind_alloc<__alloc_traits, value_type> >::value,
1061                "[allocator.requirements] states that rebinding an allocator to the same type should result in the "
1062                "original allocator");
1063
1064  static_assert((is_same<typename __table::__container_value_type, value_type>::value), "");
1065  static_assert((is_same<typename __table::__node_value_type, __value_type>::value), "");
1066
1067public:
1068  typedef typename __alloc_traits::pointer pointer;
1069  typedef typename __alloc_traits::const_pointer const_pointer;
1070  typedef typename __table::size_type size_type;
1071  typedef typename __table::difference_type difference_type;
1072
1073  typedef __hash_map_iterator<typename __table::iterator> iterator;
1074  typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
1075  typedef __hash_map_iterator<typename __table::local_iterator> local_iterator;
1076  typedef __hash_map_const_iterator<typename __table::const_local_iterator> const_local_iterator;
1077
1078#if _LIBCPP_STD_VER >= 17
1079  typedef __map_node_handle<__node, allocator_type> node_type;
1080  typedef __insert_return_type<iterator, node_type> insert_return_type;
1081#endif
1082
1083  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1084  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1085  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1086  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1087
1088  _LIBCPP_HIDE_FROM_ABI unordered_map() _NOEXCEPT_(is_nothrow_default_constructible<__table>::value) {}
1089  explicit _LIBCPP_HIDE_FROM_ABI
1090  unordered_map(size_type __n, const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
1091  _LIBCPP_HIDE_FROM_ABI
1092  unordered_map(size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a);
1093  template <class _InputIterator>
1094  _LIBCPP_HIDE_FROM_ABI unordered_map(_InputIterator __first, _InputIterator __last);
1095  template <class _InputIterator>
1096  _LIBCPP_HIDE_FROM_ABI
1097  unordered_map(_InputIterator __first,
1098                _InputIterator __last,
1099                size_type __n,
1100                const hasher& __hf     = hasher(),
1101                const key_equal& __eql = key_equal());
1102  template <class _InputIterator>
1103  _LIBCPP_HIDE_FROM_ABI unordered_map(
1104      _InputIterator __first,
1105      _InputIterator __last,
1106      size_type __n,
1107      const hasher& __hf,
1108      const key_equal& __eql,
1109      const allocator_type& __a);
1110
1111#if _LIBCPP_STD_VER >= 23
1112  template <_ContainerCompatibleRange<value_type> _Range>
1113  _LIBCPP_HIDE_FROM_ABI unordered_map(
1114      from_range_t,
1115      _Range&& __range,
1116      size_type __n             = /*implementation-defined*/ 0,
1117      const hasher& __hf        = hasher(),
1118      const key_equal& __eql    = key_equal(),
1119      const allocator_type& __a = allocator_type())
1120      : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1121    if (__n > 0) {
1122      __table_.__rehash_unique(__n);
1123    }
1124    insert_range(std::forward<_Range>(__range));
1125  }
1126#endif
1127
1128  _LIBCPP_HIDE_FROM_ABI explicit unordered_map(const allocator_type& __a);
1129  _LIBCPP_HIDE_FROM_ABI unordered_map(const unordered_map& __u);
1130  _LIBCPP_HIDE_FROM_ABI unordered_map(const unordered_map& __u, const allocator_type& __a);
1131#ifndef _LIBCPP_CXX03_LANG
1132  _LIBCPP_HIDE_FROM_ABI unordered_map(unordered_map&& __u) _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
1133  _LIBCPP_HIDE_FROM_ABI unordered_map(unordered_map&& __u, const allocator_type& __a);
1134  _LIBCPP_HIDE_FROM_ABI unordered_map(initializer_list<value_type> __il);
1135  _LIBCPP_HIDE_FROM_ABI
1136  unordered_map(initializer_list<value_type> __il,
1137                size_type __n,
1138                const hasher& __hf     = hasher(),
1139                const key_equal& __eql = key_equal());
1140  _LIBCPP_HIDE_FROM_ABI unordered_map(
1141      initializer_list<value_type> __il,
1142      size_type __n,
1143      const hasher& __hf,
1144      const key_equal& __eql,
1145      const allocator_type& __a);
1146#endif // _LIBCPP_CXX03_LANG
1147#if _LIBCPP_STD_VER >= 14
1148  _LIBCPP_HIDE_FROM_ABI unordered_map(size_type __n, const allocator_type& __a)
1149      : unordered_map(__n, hasher(), key_equal(), __a) {}
1150  _LIBCPP_HIDE_FROM_ABI unordered_map(size_type __n, const hasher& __hf, const allocator_type& __a)
1151      : unordered_map(__n, __hf, key_equal(), __a) {}
1152  template <class _InputIterator>
1153  _LIBCPP_HIDE_FROM_ABI
1154  unordered_map(_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type& __a)
1155      : unordered_map(__first, __last, __n, hasher(), key_equal(), __a) {}
1156  template <class _InputIterator>
1157  _LIBCPP_HIDE_FROM_ABI unordered_map(
1158      _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const allocator_type& __a)
1159      : unordered_map(__first, __last, __n, __hf, key_equal(), __a) {}
1160
1161#  if _LIBCPP_STD_VER >= 23
1162  template <_ContainerCompatibleRange<value_type> _Range>
1163  _LIBCPP_HIDE_FROM_ABI unordered_map(from_range_t, _Range&& __range, size_type __n, const allocator_type& __a)
1164      : unordered_map(from_range, std::forward<_Range>(__range), __n, hasher(), key_equal(), __a) {}
1165
1166  template <_ContainerCompatibleRange<value_type> _Range>
1167  _LIBCPP_HIDE_FROM_ABI
1168  unordered_map(from_range_t, _Range&& __range, size_type __n, const hasher& __hf, const allocator_type& __a)
1169      : unordered_map(from_range, std::forward<_Range>(__range), __n, __hf, key_equal(), __a) {}
1170#  endif
1171
1172  _LIBCPP_HIDE_FROM_ABI unordered_map(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
1173      : unordered_map(__il, __n, hasher(), key_equal(), __a) {}
1174  _LIBCPP_HIDE_FROM_ABI
1175  unordered_map(initializer_list<value_type> __il, size_type __n, const hasher& __hf, const allocator_type& __a)
1176      : unordered_map(__il, __n, __hf, key_equal(), __a) {}
1177#endif
1178  _LIBCPP_HIDE_FROM_ABI ~unordered_map() {
1179    static_assert(sizeof(std::__diagnose_unordered_container_requirements<_Key, _Hash, _Pred>(0)), "");
1180  }
1181
1182  _LIBCPP_HIDE_FROM_ABI unordered_map& operator=(const unordered_map& __u) {
1183#ifndef _LIBCPP_CXX03_LANG
1184    __table_ = __u.__table_;
1185#else
1186    if (this != std::addressof(__u)) {
1187      __table_.clear();
1188      __table_.hash_function()   = __u.__table_.hash_function();
1189      __table_.key_eq()          = __u.__table_.key_eq();
1190      __table_.max_load_factor() = __u.__table_.max_load_factor();
1191      __table_.__copy_assign_alloc(__u.__table_);
1192      insert(__u.begin(), __u.end());
1193    }
1194#endif
1195    return *this;
1196  }
1197#ifndef _LIBCPP_CXX03_LANG
1198  _LIBCPP_HIDE_FROM_ABI unordered_map& operator=(unordered_map&& __u)
1199      _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
1200  _LIBCPP_HIDE_FROM_ABI unordered_map& operator=(initializer_list<value_type> __il);
1201#endif // _LIBCPP_CXX03_LANG
1202
1203  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT {
1204    return allocator_type(__table_.__node_alloc());
1205  }
1206
1207  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return __table_.size() == 0; }
1208  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __table_.size(); }
1209  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __table_.max_size(); }
1210
1211  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __table_.begin(); }
1212  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __table_.end(); }
1213  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __table_.begin(); }
1214  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __table_.end(); }
1215  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return __table_.begin(); }
1216  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return __table_.end(); }
1217
1218  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(const value_type& __x) { return __table_.__insert_unique(__x); }
1219
1220  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, const value_type& __x) { return insert(__x).first; }
1221
1222  template <class _InputIterator>
1223  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last);
1224
1225#if _LIBCPP_STD_VER >= 23
1226  template <_ContainerCompatibleRange<value_type> _Range>
1227  _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
1228    for (auto&& __element : __range) {
1229      __table_.__insert_unique(std::forward<decltype(__element)>(__element));
1230    }
1231  }
1232#endif
1233
1234#ifndef _LIBCPP_CXX03_LANG
1235  _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
1236
1237  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(value_type&& __x) {
1238    return __table_.__insert_unique(std::move(__x));
1239  }
1240
1241  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, value_type&& __x) {
1242    return __table_.__insert_unique(std::move(__x)).first;
1243  }
1244
1245  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
1246  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(_Pp&& __x) {
1247    return __table_.__insert_unique(std::forward<_Pp>(__x));
1248  }
1249
1250  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
1251  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, _Pp&& __x) {
1252    return insert(std::forward<_Pp>(__x)).first;
1253  }
1254
1255  template <class... _Args>
1256  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> emplace(_Args&&... __args) {
1257    return __table_.__emplace_unique(std::forward<_Args>(__args)...);
1258  }
1259
1260  template <class... _Args>
1261  _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator, _Args&&... __args) {
1262    return __table_.__emplace_unique(std::forward<_Args>(__args)...).first;
1263  }
1264
1265#endif // _LIBCPP_CXX03_LANG
1266
1267#if _LIBCPP_STD_VER >= 17
1268  template <class... _Args>
1269  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(const key_type& __k, _Args&&... __args) {
1270    return __table_.__emplace_unique_key_args(
1271        __k, piecewise_construct, std::forward_as_tuple(__k), std::forward_as_tuple(std::forward<_Args>(__args)...));
1272  }
1273
1274  template <class... _Args>
1275  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(key_type&& __k, _Args&&... __args) {
1276    return __table_.__emplace_unique_key_args(
1277        __k,
1278        piecewise_construct,
1279        std::forward_as_tuple(std::move(__k)),
1280        std::forward_as_tuple(std::forward<_Args>(__args)...));
1281  }
1282
1283  template <class... _Args>
1284  _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator, const key_type& __k, _Args&&... __args) {
1285    return try_emplace(__k, std::forward<_Args>(__args)...).first;
1286  }
1287
1288  template <class... _Args>
1289  _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator, key_type&& __k, _Args&&... __args) {
1290    return try_emplace(std::move(__k), std::forward<_Args>(__args)...).first;
1291  }
1292
1293  template <class _Vp>
1294  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(const key_type& __k, _Vp&& __v) {
1295    pair<iterator, bool> __res = __table_.__emplace_unique_key_args(__k, __k, std::forward<_Vp>(__v));
1296    if (!__res.second) {
1297      __res.first->second = std::forward<_Vp>(__v);
1298    }
1299    return __res;
1300  }
1301
1302  template <class _Vp>
1303  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(key_type&& __k, _Vp&& __v) {
1304    pair<iterator, bool> __res = __table_.__emplace_unique_key_args(__k, std::move(__k), std::forward<_Vp>(__v));
1305    if (!__res.second) {
1306      __res.first->second = std::forward<_Vp>(__v);
1307    }
1308    return __res;
1309  }
1310
1311  template <class _Vp>
1312  _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator, const key_type& __k, _Vp&& __v) {
1313    return insert_or_assign(__k, std::forward<_Vp>(__v)).first;
1314  }
1315
1316  template <class _Vp>
1317  _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator, key_type&& __k, _Vp&& __v) {
1318    return insert_or_assign(std::move(__k), std::forward<_Vp>(__v)).first;
1319  }
1320#endif // _LIBCPP_STD_VER >= 17
1321
1322  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p) { return __table_.erase(__p.__i_); }
1323  _LIBCPP_HIDE_FROM_ABI iterator erase(iterator __p) { return __table_.erase(__p.__i_); }
1324  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __table_.__erase_unique(__k); }
1325  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last) {
1326    return __table_.erase(__first.__i_, __last.__i_);
1327  }
1328  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __table_.clear(); }
1329
1330#if _LIBCPP_STD_VER >= 17
1331  _LIBCPP_HIDE_FROM_ABI insert_return_type insert(node_type&& __nh) {
1332    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
1333                                        "node_type with incompatible allocator passed to unordered_map::insert()");
1334    return __table_.template __node_handle_insert_unique< node_type, insert_return_type>(std::move(__nh));
1335  }
1336  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, node_type&& __nh) {
1337    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
1338                                        "node_type with incompatible allocator passed to unordered_map::insert()");
1339    return __table_.template __node_handle_insert_unique<node_type>(__hint.__i_, std::move(__nh));
1340  }
1341  _LIBCPP_HIDE_FROM_ABI node_type extract(key_type const& __key) {
1342    return __table_.template __node_handle_extract<node_type>(__key);
1343  }
1344  _LIBCPP_HIDE_FROM_ABI node_type extract(const_iterator __it) {
1345    return __table_.template __node_handle_extract<node_type>(__it.__i_);
1346  }
1347
1348  template <class _H2, class _P2>
1349  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
1350    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1351        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1352    return __table_.__node_handle_merge_unique(__source.__table_);
1353  }
1354  template <class _H2, class _P2>
1355  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
1356    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1357        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1358    return __table_.__node_handle_merge_unique(__source.__table_);
1359  }
1360  template <class _H2, class _P2>
1361  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
1362    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1363        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1364    return __table_.__node_handle_merge_unique(__source.__table_);
1365  }
1366  template <class _H2, class _P2>
1367  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
1368    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1369        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1370    return __table_.__node_handle_merge_unique(__source.__table_);
1371  }
1372#endif
1373
1374  _LIBCPP_HIDE_FROM_ABI void swap(unordered_map& __u) _NOEXCEPT_(__is_nothrow_swappable<__table>::value) {
1375    __table_.swap(__u.__table_);
1376  }
1377
1378  _LIBCPP_HIDE_FROM_ABI hasher hash_function() const { return __table_.hash_function().hash_function(); }
1379  _LIBCPP_HIDE_FROM_ABI key_equal key_eq() const { return __table_.key_eq().key_eq(); }
1380
1381  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __table_.find(__k); }
1382  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __table_.find(__k); }
1383#if _LIBCPP_STD_VER >= 20
1384  template <class _K2,
1385            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1386  _LIBCPP_HIDE_FROM_ABI iterator find(const _K2& __k) {
1387    return __table_.find(__k);
1388  }
1389  template <class _K2,
1390            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1391  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _K2& __k) const {
1392    return __table_.find(__k);
1393  }
1394#endif // _LIBCPP_STD_VER >= 20
1395
1396  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __table_.__count_unique(__k); }
1397#if _LIBCPP_STD_VER >= 20
1398  template <class _K2,
1399            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1400  _LIBCPP_HIDE_FROM_ABI size_type count(const _K2& __k) const {
1401    return __table_.__count_unique(__k);
1402  }
1403#endif // _LIBCPP_STD_VER >= 20
1404
1405#if _LIBCPP_STD_VER >= 20
1406  _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __k) const { return find(__k) != end(); }
1407
1408  template <class _K2,
1409            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1410  _LIBCPP_HIDE_FROM_ABI bool contains(const _K2& __k) const {
1411    return find(__k) != end();
1412  }
1413#endif // _LIBCPP_STD_VER >= 20
1414
1415  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __k) {
1416    return __table_.__equal_range_unique(__k);
1417  }
1418  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
1419    return __table_.__equal_range_unique(__k);
1420  }
1421#if _LIBCPP_STD_VER >= 20
1422  template <class _K2,
1423            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1424  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _K2& __k) {
1425    return __table_.__equal_range_unique(__k);
1426  }
1427  template <class _K2,
1428            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1429  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _K2& __k) const {
1430    return __table_.__equal_range_unique(__k);
1431  }
1432#endif // _LIBCPP_STD_VER >= 20
1433
1434  _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](const key_type& __k);
1435#ifndef _LIBCPP_CXX03_LANG
1436  _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](key_type&& __k);
1437#endif
1438
1439  _LIBCPP_HIDE_FROM_ABI mapped_type& at(const key_type& __k);
1440  _LIBCPP_HIDE_FROM_ABI const mapped_type& at(const key_type& __k) const;
1441
1442  _LIBCPP_HIDE_FROM_ABI size_type bucket_count() const _NOEXCEPT { return __table_.bucket_count(); }
1443  _LIBCPP_HIDE_FROM_ABI size_type max_bucket_count() const _NOEXCEPT { return __table_.max_bucket_count(); }
1444
1445  _LIBCPP_HIDE_FROM_ABI size_type bucket_size(size_type __n) const { return __table_.bucket_size(__n); }
1446  _LIBCPP_HIDE_FROM_ABI size_type bucket(const key_type& __k) const { return __table_.bucket(__k); }
1447
1448  _LIBCPP_HIDE_FROM_ABI local_iterator begin(size_type __n) { return __table_.begin(__n); }
1449  _LIBCPP_HIDE_FROM_ABI local_iterator end(size_type __n) { return __table_.end(__n); }
1450  _LIBCPP_HIDE_FROM_ABI const_local_iterator begin(size_type __n) const { return __table_.cbegin(__n); }
1451  _LIBCPP_HIDE_FROM_ABI const_local_iterator end(size_type __n) const { return __table_.cend(__n); }
1452  _LIBCPP_HIDE_FROM_ABI const_local_iterator cbegin(size_type __n) const { return __table_.cbegin(__n); }
1453  _LIBCPP_HIDE_FROM_ABI const_local_iterator cend(size_type __n) const { return __table_.cend(__n); }
1454
1455  _LIBCPP_HIDE_FROM_ABI float load_factor() const _NOEXCEPT { return __table_.load_factor(); }
1456  _LIBCPP_HIDE_FROM_ABI float max_load_factor() const _NOEXCEPT { return __table_.max_load_factor(); }
1457  _LIBCPP_HIDE_FROM_ABI void max_load_factor(float __mlf) { __table_.max_load_factor(__mlf); }
1458  _LIBCPP_HIDE_FROM_ABI void rehash(size_type __n) { __table_.__rehash_unique(__n); }
1459  _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n) { __table_.__reserve_unique(__n); }
1460
1461private:
1462#ifdef _LIBCPP_CXX03_LANG
1463  _LIBCPP_HIDE_FROM_ABI __node_holder __construct_node_with_key(const key_type& __k);
1464#endif
1465};
1466
1467#if _LIBCPP_STD_VER >= 17
1468template <class _InputIterator,
1469          class _Hash      = hash<__iter_key_type<_InputIterator>>,
1470          class _Pred      = equal_to<__iter_key_type<_InputIterator>>,
1471          class _Allocator = allocator<__iter_to_alloc_type<_InputIterator>>,
1472          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1473          class            = enable_if_t<!__is_allocator<_Hash>::value>,
1474          class            = enable_if_t<!is_integral<_Hash>::value>,
1475          class            = enable_if_t<!__is_allocator<_Pred>::value>,
1476          class            = enable_if_t<__is_allocator<_Allocator>::value>>
1477unordered_map(_InputIterator,
1478              _InputIterator,
1479              typename allocator_traits<_Allocator>::size_type = 0,
1480              _Hash                                            = _Hash(),
1481              _Pred                                            = _Pred(),
1482              _Allocator                                       = _Allocator())
1483    -> unordered_map<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>, _Hash, _Pred, _Allocator>;
1484
1485#  if _LIBCPP_STD_VER >= 23
1486template <ranges::input_range _Range,
1487          class _Hash      = hash<__range_key_type<_Range>>,
1488          class _Pred      = equal_to<__range_key_type<_Range>>,
1489          class _Allocator = allocator<__range_to_alloc_type<_Range>>,
1490          class            = enable_if_t<!__is_allocator<_Hash>::value>,
1491          class            = enable_if_t<!is_integral<_Hash>::value>,
1492          class            = enable_if_t<!__is_allocator<_Pred>::value>,
1493          class            = enable_if_t<__is_allocator<_Allocator>::value>>
1494unordered_map(from_range_t,
1495              _Range&&,
1496              typename allocator_traits<_Allocator>::size_type = 0,
1497              _Hash                                            = _Hash(),
1498              _Pred                                            = _Pred(),
1499              _Allocator                                       = _Allocator())
1500    -> unordered_map<__range_key_type<_Range>, __range_mapped_type<_Range>, _Hash, _Pred, _Allocator>; // C++23
1501#  endif
1502
1503template <class _Key,
1504          class _Tp,
1505          class _Hash      = hash<remove_const_t<_Key>>,
1506          class _Pred      = equal_to<remove_const_t<_Key>>,
1507          class _Allocator = allocator<pair<const _Key, _Tp>>,
1508          class            = enable_if_t<!__is_allocator<_Hash>::value>,
1509          class            = enable_if_t<!is_integral<_Hash>::value>,
1510          class            = enable_if_t<!__is_allocator<_Pred>::value>,
1511          class            = enable_if_t<__is_allocator<_Allocator>::value>>
1512unordered_map(initializer_list<pair<_Key, _Tp>>,
1513              typename allocator_traits<_Allocator>::size_type = 0,
1514              _Hash                                            = _Hash(),
1515              _Pred                                            = _Pred(),
1516              _Allocator = _Allocator()) -> unordered_map<remove_const_t<_Key>, _Tp, _Hash, _Pred, _Allocator>;
1517
1518template <class _InputIterator,
1519          class _Allocator,
1520          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1521          class = enable_if_t<__is_allocator<_Allocator>::value>>
1522unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
1523    -> unordered_map<__iter_key_type<_InputIterator>,
1524                     __iter_mapped_type<_InputIterator>,
1525                     hash<__iter_key_type<_InputIterator>>,
1526                     equal_to<__iter_key_type<_InputIterator>>,
1527                     _Allocator>;
1528
1529template <class _InputIterator,
1530          class _Allocator,
1531          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1532          class = enable_if_t<__is_allocator<_Allocator>::value>>
1533unordered_map(_InputIterator, _InputIterator, _Allocator)
1534    -> unordered_map<__iter_key_type<_InputIterator>,
1535                     __iter_mapped_type<_InputIterator>,
1536                     hash<__iter_key_type<_InputIterator>>,
1537                     equal_to<__iter_key_type<_InputIterator>>,
1538                     _Allocator>;
1539
1540template <class _InputIterator,
1541          class _Hash,
1542          class _Allocator,
1543          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1544          class = enable_if_t<!__is_allocator<_Hash>::value>,
1545          class = enable_if_t<!is_integral<_Hash>::value>,
1546          class = enable_if_t<__is_allocator<_Allocator>::value>>
1547unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1548    -> unordered_map<__iter_key_type<_InputIterator>,
1549                     __iter_mapped_type<_InputIterator>,
1550                     _Hash,
1551                     equal_to<__iter_key_type<_InputIterator>>,
1552                     _Allocator>;
1553
1554#  if _LIBCPP_STD_VER >= 23
1555
1556template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1557unordered_map(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Allocator)
1558    -> unordered_map<__range_key_type<_Range>,
1559                     __range_mapped_type<_Range>,
1560                     hash<__range_key_type<_Range>>,
1561                     equal_to<__range_key_type<_Range>>,
1562                     _Allocator>;
1563
1564template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1565unordered_map(from_range_t, _Range&&, _Allocator)
1566    -> unordered_map<__range_key_type<_Range>,
1567                     __range_mapped_type<_Range>,
1568                     hash<__range_key_type<_Range>>,
1569                     equal_to<__range_key_type<_Range>>,
1570                     _Allocator>;
1571
1572template <ranges::input_range _Range,
1573          class _Hash,
1574          class _Allocator,
1575          class = enable_if_t<!__is_allocator<_Hash>::value>,
1576          class = enable_if_t<!is_integral<_Hash>::value>,
1577          class = enable_if_t<__is_allocator<_Allocator>::value>>
1578unordered_map(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1579    -> unordered_map<__range_key_type<_Range>,
1580                     __range_mapped_type<_Range>,
1581                     _Hash,
1582                     equal_to<__range_key_type<_Range>>,
1583                     _Allocator>;
1584
1585#  endif
1586
1587template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1588unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Allocator)
1589    -> unordered_map<remove_const_t<_Key>, _Tp, hash<remove_const_t<_Key>>, equal_to<remove_const_t<_Key>>, _Allocator>;
1590
1591template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1592unordered_map(initializer_list<pair<_Key, _Tp>>, _Allocator)
1593    -> unordered_map<remove_const_t<_Key>, _Tp, hash<remove_const_t<_Key>>, equal_to<remove_const_t<_Key>>, _Allocator>;
1594
1595template <class _Key,
1596          class _Tp,
1597          class _Hash,
1598          class _Allocator,
1599          class = enable_if_t<!__is_allocator<_Hash>::value>,
1600          class = enable_if_t<!is_integral<_Hash>::value>,
1601          class = enable_if_t<__is_allocator<_Allocator>::value>>
1602unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1603    -> unordered_map<remove_const_t<_Key>, _Tp, _Hash, equal_to<remove_const_t<_Key>>, _Allocator>;
1604#endif
1605
1606template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1607unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(size_type __n, const hasher& __hf, const key_equal& __eql)
1608    : __table_(__hf, __eql) {
1609  __table_.__rehash_unique(__n);
1610}
1611
1612template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1613unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1614    size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
1615    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1616  __table_.__rehash_unique(__n);
1617}
1618
1619template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1620inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(const allocator_type& __a)
1621    : __table_(typename __table::allocator_type(__a)) {}
1622
1623template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1624template <class _InputIterator>
1625unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(_InputIterator __first, _InputIterator __last) {
1626  insert(__first, __last);
1627}
1628
1629template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1630template <class _InputIterator>
1631unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1632    _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const key_equal& __eql)
1633    : __table_(__hf, __eql) {
1634  __table_.__rehash_unique(__n);
1635  insert(__first, __last);
1636}
1637
1638template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1639template <class _InputIterator>
1640unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1641    _InputIterator __first,
1642    _InputIterator __last,
1643    size_type __n,
1644    const hasher& __hf,
1645    const key_equal& __eql,
1646    const allocator_type& __a)
1647    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1648  __table_.__rehash_unique(__n);
1649  insert(__first, __last);
1650}
1651
1652template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1653unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(const unordered_map& __u) : __table_(__u.__table_) {
1654  __table_.__rehash_unique(__u.bucket_count());
1655  insert(__u.begin(), __u.end());
1656}
1657
1658template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1659unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(const unordered_map& __u, const allocator_type& __a)
1660    : __table_(__u.__table_, typename __table::allocator_type(__a)) {
1661  __table_.__rehash_unique(__u.bucket_count());
1662  insert(__u.begin(), __u.end());
1663}
1664
1665#ifndef _LIBCPP_CXX03_LANG
1666
1667template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1668inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(unordered_map&& __u)
1669    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
1670    : __table_(std::move(__u.__table_)) {}
1671
1672template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1673unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(unordered_map&& __u, const allocator_type& __a)
1674    : __table_(std::move(__u.__table_), typename __table::allocator_type(__a)) {
1675  if (__a != __u.get_allocator()) {
1676    iterator __i = __u.begin();
1677    while (__u.size() != 0) {
1678      __table_.__emplace_unique(__u.__table_.remove((__i++).__i_)->__get_value().__move());
1679    }
1680  }
1681}
1682
1683template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1684unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(initializer_list<value_type> __il) {
1685  insert(__il.begin(), __il.end());
1686}
1687
1688template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1689unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1690    initializer_list<value_type> __il, size_type __n, const hasher& __hf, const key_equal& __eql)
1691    : __table_(__hf, __eql) {
1692  __table_.__rehash_unique(__n);
1693  insert(__il.begin(), __il.end());
1694}
1695
1696template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1697unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1698    initializer_list<value_type> __il,
1699    size_type __n,
1700    const hasher& __hf,
1701    const key_equal& __eql,
1702    const allocator_type& __a)
1703    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1704  __table_.__rehash_unique(__n);
1705  insert(__il.begin(), __il.end());
1706}
1707
1708template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1709inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&
1710unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(unordered_map&& __u)
1711    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value) {
1712  __table_ = std::move(__u.__table_);
1713  return *this;
1714}
1715
1716template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1717inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&
1718unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(initializer_list<value_type> __il) {
1719  __table_.__assign_unique(__il.begin(), __il.end());
1720  return *this;
1721}
1722
1723#endif // _LIBCPP_CXX03_LANG
1724
1725template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1726template <class _InputIterator>
1727inline void unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first, _InputIterator __last) {
1728  for (; __first != __last; ++__first)
1729    __table_.__insert_unique(*__first);
1730}
1731
1732#ifndef _LIBCPP_CXX03_LANG
1733
1734template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1735_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k) {
1736  return __table_
1737      .__emplace_unique_key_args(__k, piecewise_construct, std::forward_as_tuple(__k), std::forward_as_tuple())
1738      .first->__get_value()
1739      .second;
1740}
1741
1742template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1743_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](key_type&& __k) {
1744  return __table_
1745      .__emplace_unique_key_args(
1746          __k, piecewise_construct, std::forward_as_tuple(std::move(__k)), std::forward_as_tuple())
1747      .first->__get_value()
1748      .second;
1749}
1750#else // _LIBCPP_CXX03_LANG
1751
1752template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1753typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
1754unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node_with_key(const key_type& __k) {
1755  __node_allocator& __na = __table_.__node_alloc();
1756  __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
1757  __node_traits::construct(__na, std::addressof(__h->__get_value().__get_value().first), __k);
1758  __h.get_deleter().__first_constructed = true;
1759  __node_traits::construct(__na, std::addressof(__h->__get_value().__get_value().second));
1760  __h.get_deleter().__second_constructed = true;
1761  return __h;
1762}
1763
1764template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1765_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k) {
1766  iterator __i = find(__k);
1767  if (__i != end())
1768    return __i->second;
1769  __node_holder __h        = __construct_node_with_key(__k);
1770  pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
1771  __h.release();
1772  return __r.first->second;
1773}
1774
1775#endif // _LIBCPP_CXX03_LANG
1776
1777template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1778_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k) {
1779  iterator __i = find(__k);
1780  if (__i == end())
1781    __throw_out_of_range("unordered_map::at: key not found");
1782  return __i->second;
1783}
1784
1785template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1786const _Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k) const {
1787  const_iterator __i = find(__k);
1788  if (__i == end())
1789    __throw_out_of_range("unordered_map::at: key not found");
1790  return __i->second;
1791}
1792
1793template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1794inline _LIBCPP_HIDE_FROM_ABI void
1795swap(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
1796    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
1797  __x.swap(__y);
1798}
1799
1800#if _LIBCPP_STD_VER >= 20
1801template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc, class _Predicate>
1802inline _LIBCPP_HIDE_FROM_ABI typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::size_type
1803erase_if(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __c, _Predicate __pred) {
1804  return std::__libcpp_erase_if_container(__c, __pred);
1805}
1806#endif
1807
1808template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1809_LIBCPP_HIDE_FROM_ABI bool operator==(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
1810                                      const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
1811  if (__x.size() != __y.size())
1812    return false;
1813  typedef typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
1814  for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end(); __i != __ex; ++__i) {
1815    const_iterator __j = __y.find(__i->first);
1816    if (__j == __ey || !(*__i == *__j))
1817      return false;
1818  }
1819  return true;
1820}
1821
1822#if _LIBCPP_STD_VER <= 17
1823
1824template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1825inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
1826                                             const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
1827  return !(__x == __y);
1828}
1829
1830#endif
1831
1832template <class _Key,
1833          class _Tp,
1834          class _Hash  = hash<_Key>,
1835          class _Pred  = equal_to<_Key>,
1836          class _Alloc = allocator<pair<const _Key, _Tp> > >
1837class _LIBCPP_TEMPLATE_VIS unordered_multimap {
1838public:
1839  // types
1840  typedef _Key key_type;
1841  typedef _Tp mapped_type;
1842  typedef __type_identity_t<_Hash> hasher;
1843  typedef __type_identity_t<_Pred> key_equal;
1844  typedef __type_identity_t<_Alloc> allocator_type;
1845  typedef pair<const key_type, mapped_type> value_type;
1846  typedef value_type& reference;
1847  typedef const value_type& const_reference;
1848  static_assert((is_same<value_type, typename allocator_type::value_type>::value),
1849                "Allocator::value_type must be same type as value_type");
1850
1851private:
1852  typedef __hash_value_type<key_type, mapped_type> __value_type;
1853  typedef __unordered_map_hasher<key_type, __value_type, hasher, key_equal> __hasher;
1854  typedef __unordered_map_equal<key_type, __value_type, key_equal, hasher> __key_equal;
1855  typedef __rebind_alloc<allocator_traits<allocator_type>, __value_type> __allocator_type;
1856
1857  typedef __hash_table<__value_type, __hasher, __key_equal, __allocator_type> __table;
1858
1859  __table __table_;
1860
1861  typedef typename __table::_NodeTypes _NodeTypes;
1862  typedef typename __table::__node_traits __node_traits;
1863  typedef typename __table::__node_allocator __node_allocator;
1864  typedef typename __table::__node __node;
1865  typedef __hash_map_node_destructor<__node_allocator> _Dp;
1866  typedef unique_ptr<__node, _Dp> __node_holder;
1867  typedef allocator_traits<allocator_type> __alloc_traits;
1868  static_assert((is_same<typename __node_traits::size_type, typename __alloc_traits::size_type>::value),
1869                "Allocator uses different size_type for different types");
1870
1871  static_assert(is_same<allocator_type, __rebind_alloc<__alloc_traits, value_type> >::value,
1872                "[allocator.requirements] states that rebinding an allocator to the same type should result in the "
1873                "original allocator");
1874
1875public:
1876  typedef typename __alloc_traits::pointer pointer;
1877  typedef typename __alloc_traits::const_pointer const_pointer;
1878  typedef typename __table::size_type size_type;
1879  typedef typename __table::difference_type difference_type;
1880
1881  typedef __hash_map_iterator<typename __table::iterator> iterator;
1882  typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
1883  typedef __hash_map_iterator<typename __table::local_iterator> local_iterator;
1884  typedef __hash_map_const_iterator<typename __table::const_local_iterator> const_local_iterator;
1885
1886#if _LIBCPP_STD_VER >= 17
1887  typedef __map_node_handle<__node, allocator_type> node_type;
1888#endif
1889
1890  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1891  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1892  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1893  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1894
1895  _LIBCPP_HIDE_FROM_ABI unordered_multimap() _NOEXCEPT_(is_nothrow_default_constructible<__table>::value) {}
1896  explicit _LIBCPP_HIDE_FROM_ABI
1897  unordered_multimap(size_type __n, const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
1898  _LIBCPP_HIDE_FROM_ABI
1899  unordered_multimap(size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a);
1900  template <class _InputIterator>
1901  _LIBCPP_HIDE_FROM_ABI unordered_multimap(_InputIterator __first, _InputIterator __last);
1902  template <class _InputIterator>
1903  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1904      _InputIterator __first,
1905      _InputIterator __last,
1906      size_type __n,
1907      const hasher& __hf     = hasher(),
1908      const key_equal& __eql = key_equal());
1909  template <class _InputIterator>
1910  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1911      _InputIterator __first,
1912      _InputIterator __last,
1913      size_type __n,
1914      const hasher& __hf,
1915      const key_equal& __eql,
1916      const allocator_type& __a);
1917
1918#if _LIBCPP_STD_VER >= 23
1919  template <_ContainerCompatibleRange<value_type> _Range>
1920  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1921      from_range_t,
1922      _Range&& __range,
1923      size_type __n             = /*implementation-defined*/ 0,
1924      const hasher& __hf        = hasher(),
1925      const key_equal& __eql    = key_equal(),
1926      const allocator_type& __a = allocator_type())
1927      : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1928    if (__n > 0) {
1929      __table_.__rehash_multi(__n);
1930    }
1931    insert_range(std::forward<_Range>(__range));
1932  }
1933#endif
1934
1935  _LIBCPP_HIDE_FROM_ABI explicit unordered_multimap(const allocator_type& __a);
1936  _LIBCPP_HIDE_FROM_ABI unordered_multimap(const unordered_multimap& __u);
1937  _LIBCPP_HIDE_FROM_ABI unordered_multimap(const unordered_multimap& __u, const allocator_type& __a);
1938#ifndef _LIBCPP_CXX03_LANG
1939  _LIBCPP_HIDE_FROM_ABI unordered_multimap(unordered_multimap&& __u)
1940      _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
1941  _LIBCPP_HIDE_FROM_ABI unordered_multimap(unordered_multimap&& __u, const allocator_type& __a);
1942  _LIBCPP_HIDE_FROM_ABI unordered_multimap(initializer_list<value_type> __il);
1943  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1944      initializer_list<value_type> __il,
1945      size_type __n,
1946      const hasher& __hf     = hasher(),
1947      const key_equal& __eql = key_equal());
1948  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1949      initializer_list<value_type> __il,
1950      size_type __n,
1951      const hasher& __hf,
1952      const key_equal& __eql,
1953      const allocator_type& __a);
1954#endif // _LIBCPP_CXX03_LANG
1955#if _LIBCPP_STD_VER >= 14
1956  _LIBCPP_HIDE_FROM_ABI unordered_multimap(size_type __n, const allocator_type& __a)
1957      : unordered_multimap(__n, hasher(), key_equal(), __a) {}
1958  _LIBCPP_HIDE_FROM_ABI unordered_multimap(size_type __n, const hasher& __hf, const allocator_type& __a)
1959      : unordered_multimap(__n, __hf, key_equal(), __a) {}
1960  template <class _InputIterator>
1961  _LIBCPP_HIDE_FROM_ABI
1962  unordered_multimap(_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type& __a)
1963      : unordered_multimap(__first, __last, __n, hasher(), key_equal(), __a) {}
1964  template <class _InputIterator>
1965  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1966      _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const allocator_type& __a)
1967      : unordered_multimap(__first, __last, __n, __hf, key_equal(), __a) {}
1968
1969#  if _LIBCPP_STD_VER >= 23
1970  template <_ContainerCompatibleRange<value_type> _Range>
1971  _LIBCPP_HIDE_FROM_ABI unordered_multimap(from_range_t, _Range&& __range, size_type __n, const allocator_type& __a)
1972      : unordered_multimap(from_range, std::forward<_Range>(__range), __n, hasher(), key_equal(), __a) {}
1973
1974  template <_ContainerCompatibleRange<value_type> _Range>
1975  _LIBCPP_HIDE_FROM_ABI
1976  unordered_multimap(from_range_t, _Range&& __range, size_type __n, const hasher& __hf, const allocator_type& __a)
1977      : unordered_multimap(from_range, std::forward<_Range>(__range), __n, __hf, key_equal(), __a) {}
1978#  endif
1979
1980  _LIBCPP_HIDE_FROM_ABI unordered_multimap(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
1981      : unordered_multimap(__il, __n, hasher(), key_equal(), __a) {}
1982  _LIBCPP_HIDE_FROM_ABI
1983  unordered_multimap(initializer_list<value_type> __il, size_type __n, const hasher& __hf, const allocator_type& __a)
1984      : unordered_multimap(__il, __n, __hf, key_equal(), __a) {}
1985#endif
1986  _LIBCPP_HIDE_FROM_ABI ~unordered_multimap() {
1987    static_assert(sizeof(std::__diagnose_unordered_container_requirements<_Key, _Hash, _Pred>(0)), "");
1988  }
1989
1990  _LIBCPP_HIDE_FROM_ABI unordered_multimap& operator=(const unordered_multimap& __u) {
1991#ifndef _LIBCPP_CXX03_LANG
1992    __table_ = __u.__table_;
1993#else
1994    if (this != std::addressof(__u)) {
1995      __table_.clear();
1996      __table_.hash_function()   = __u.__table_.hash_function();
1997      __table_.key_eq()          = __u.__table_.key_eq();
1998      __table_.max_load_factor() = __u.__table_.max_load_factor();
1999      __table_.__copy_assign_alloc(__u.__table_);
2000      insert(__u.begin(), __u.end());
2001    }
2002#endif
2003    return *this;
2004  }
2005#ifndef _LIBCPP_CXX03_LANG
2006  _LIBCPP_HIDE_FROM_ABI unordered_multimap& operator=(unordered_multimap&& __u)
2007      _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
2008  _LIBCPP_HIDE_FROM_ABI unordered_multimap& operator=(initializer_list<value_type> __il);
2009#endif // _LIBCPP_CXX03_LANG
2010
2011  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT {
2012    return allocator_type(__table_.__node_alloc());
2013  }
2014
2015  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return __table_.size() == 0; }
2016  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __table_.size(); }
2017  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __table_.max_size(); }
2018
2019  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __table_.begin(); }
2020  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __table_.end(); }
2021  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __table_.begin(); }
2022  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __table_.end(); }
2023  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return __table_.begin(); }
2024  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return __table_.end(); }
2025
2026  _LIBCPP_HIDE_FROM_ABI iterator insert(const value_type& __x) { return __table_.__insert_multi(__x); }
2027
2028  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, const value_type& __x) {
2029    return __table_.__insert_multi(__p.__i_, __x);
2030  }
2031
2032  template <class _InputIterator>
2033  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last);
2034
2035#if _LIBCPP_STD_VER >= 23
2036  template <_ContainerCompatibleRange<value_type> _Range>
2037  _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
2038    for (auto&& __element : __range) {
2039      __table_.__insert_multi(std::forward<decltype(__element)>(__element));
2040    }
2041  }
2042#endif
2043
2044#ifndef _LIBCPP_CXX03_LANG
2045  _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
2046  _LIBCPP_HIDE_FROM_ABI iterator insert(value_type&& __x) { return __table_.__insert_multi(std::move(__x)); }
2047
2048  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, value_type&& __x) {
2049    return __table_.__insert_multi(__p.__i_, std::move(__x));
2050  }
2051
2052  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
2053  _LIBCPP_HIDE_FROM_ABI iterator insert(_Pp&& __x) {
2054    return __table_.__insert_multi(std::forward<_Pp>(__x));
2055  }
2056
2057  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
2058  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, _Pp&& __x) {
2059    return __table_.__insert_multi(__p.__i_, std::forward<_Pp>(__x));
2060  }
2061
2062  template <class... _Args>
2063  _LIBCPP_HIDE_FROM_ABI iterator emplace(_Args&&... __args) {
2064    return __table_.__emplace_multi(std::forward<_Args>(__args)...);
2065  }
2066
2067  template <class... _Args>
2068  _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator __p, _Args&&... __args) {
2069    return __table_.__emplace_hint_multi(__p.__i_, std::forward<_Args>(__args)...);
2070  }
2071#endif // _LIBCPP_CXX03_LANG
2072
2073  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p) { return __table_.erase(__p.__i_); }
2074  _LIBCPP_HIDE_FROM_ABI iterator erase(iterator __p) { return __table_.erase(__p.__i_); }
2075  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __table_.__erase_multi(__k); }
2076  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last) {
2077    return __table_.erase(__first.__i_, __last.__i_);
2078  }
2079  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __table_.clear(); }
2080
2081#if _LIBCPP_STD_VER >= 17
2082  _LIBCPP_HIDE_FROM_ABI iterator insert(node_type&& __nh) {
2083    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
2084                                        "node_type with incompatible allocator passed to unordered_multimap::insert()");
2085    return __table_.template __node_handle_insert_multi<node_type>(std::move(__nh));
2086  }
2087  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, node_type&& __nh) {
2088    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
2089                                        "node_type with incompatible allocator passed to unordered_multimap::insert()");
2090    return __table_.template __node_handle_insert_multi<node_type>(__hint.__i_, std::move(__nh));
2091  }
2092  _LIBCPP_HIDE_FROM_ABI node_type extract(key_type const& __key) {
2093    return __table_.template __node_handle_extract<node_type>(__key);
2094  }
2095  _LIBCPP_HIDE_FROM_ABI node_type extract(const_iterator __it) {
2096    return __table_.template __node_handle_extract<node_type>(__it.__i_);
2097  }
2098
2099  template <class _H2, class _P2>
2100  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
2101    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2102        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2103    return __table_.__node_handle_merge_multi(__source.__table_);
2104  }
2105  template <class _H2, class _P2>
2106  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
2107    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2108        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2109    return __table_.__node_handle_merge_multi(__source.__table_);
2110  }
2111  template <class _H2, class _P2>
2112  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
2113    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2114        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2115    return __table_.__node_handle_merge_multi(__source.__table_);
2116  }
2117  template <class _H2, class _P2>
2118  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
2119    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2120        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2121    return __table_.__node_handle_merge_multi(__source.__table_);
2122  }
2123#endif
2124
2125  _LIBCPP_HIDE_FROM_ABI void swap(unordered_multimap& __u) _NOEXCEPT_(__is_nothrow_swappable<__table>::value) {
2126    __table_.swap(__u.__table_);
2127  }
2128
2129  _LIBCPP_HIDE_FROM_ABI hasher hash_function() const { return __table_.hash_function().hash_function(); }
2130  _LIBCPP_HIDE_FROM_ABI key_equal key_eq() const { return __table_.key_eq().key_eq(); }
2131
2132  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __table_.find(__k); }
2133  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __table_.find(__k); }
2134#if _LIBCPP_STD_VER >= 20
2135  template <class _K2,
2136            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2137  _LIBCPP_HIDE_FROM_ABI iterator find(const _K2& __k) {
2138    return __table_.find(__k);
2139  }
2140  template <class _K2,
2141            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2142  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _K2& __k) const {
2143    return __table_.find(__k);
2144  }
2145#endif // _LIBCPP_STD_VER >= 20
2146
2147  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __table_.__count_multi(__k); }
2148#if _LIBCPP_STD_VER >= 20
2149  template <class _K2,
2150            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2151  _LIBCPP_HIDE_FROM_ABI size_type count(const _K2& __k) const {
2152    return __table_.__count_multi(__k);
2153  }
2154#endif // _LIBCPP_STD_VER >= 20
2155
2156#if _LIBCPP_STD_VER >= 20
2157  _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __k) const { return find(__k) != end(); }
2158
2159  template <class _K2,
2160            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2161  _LIBCPP_HIDE_FROM_ABI bool contains(const _K2& __k) const {
2162    return find(__k) != end();
2163  }
2164#endif // _LIBCPP_STD_VER >= 20
2165
2166  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __k) {
2167    return __table_.__equal_range_multi(__k);
2168  }
2169  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
2170    return __table_.__equal_range_multi(__k);
2171  }
2172#if _LIBCPP_STD_VER >= 20
2173  template <class _K2,
2174            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2175  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _K2& __k) {
2176    return __table_.__equal_range_multi(__k);
2177  }
2178  template <class _K2,
2179            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2180  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _K2& __k) const {
2181    return __table_.__equal_range_multi(__k);
2182  }
2183#endif // _LIBCPP_STD_VER >= 20
2184
2185  _LIBCPP_HIDE_FROM_ABI size_type bucket_count() const _NOEXCEPT { return __table_.bucket_count(); }
2186  _LIBCPP_HIDE_FROM_ABI size_type max_bucket_count() const _NOEXCEPT { return __table_.max_bucket_count(); }
2187
2188  _LIBCPP_HIDE_FROM_ABI size_type bucket_size(size_type __n) const { return __table_.bucket_size(__n); }
2189  _LIBCPP_HIDE_FROM_ABI size_type bucket(const key_type& __k) const { return __table_.bucket(__k); }
2190
2191  _LIBCPP_HIDE_FROM_ABI local_iterator begin(size_type __n) { return __table_.begin(__n); }
2192  _LIBCPP_HIDE_FROM_ABI local_iterator end(size_type __n) { return __table_.end(__n); }
2193  _LIBCPP_HIDE_FROM_ABI const_local_iterator begin(size_type __n) const { return __table_.cbegin(__n); }
2194  _LIBCPP_HIDE_FROM_ABI const_local_iterator end(size_type __n) const { return __table_.cend(__n); }
2195  _LIBCPP_HIDE_FROM_ABI const_local_iterator cbegin(size_type __n) const { return __table_.cbegin(__n); }
2196  _LIBCPP_HIDE_FROM_ABI const_local_iterator cend(size_type __n) const { return __table_.cend(__n); }
2197
2198  _LIBCPP_HIDE_FROM_ABI float load_factor() const _NOEXCEPT { return __table_.load_factor(); }
2199  _LIBCPP_HIDE_FROM_ABI float max_load_factor() const _NOEXCEPT { return __table_.max_load_factor(); }
2200  _LIBCPP_HIDE_FROM_ABI void max_load_factor(float __mlf) { __table_.max_load_factor(__mlf); }
2201  _LIBCPP_HIDE_FROM_ABI void rehash(size_type __n) { __table_.__rehash_multi(__n); }
2202  _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n) { __table_.__reserve_multi(__n); }
2203};
2204
2205#if _LIBCPP_STD_VER >= 17
2206template <class _InputIterator,
2207          class _Hash      = hash<__iter_key_type<_InputIterator>>,
2208          class _Pred      = equal_to<__iter_key_type<_InputIterator>>,
2209          class _Allocator = allocator<__iter_to_alloc_type<_InputIterator>>,
2210          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2211          class            = enable_if_t<!__is_allocator<_Hash>::value>,
2212          class            = enable_if_t<!is_integral<_Hash>::value>,
2213          class            = enable_if_t<!__is_allocator<_Pred>::value>,
2214          class            = enable_if_t<__is_allocator<_Allocator>::value>>
2215unordered_multimap(_InputIterator,
2216                   _InputIterator,
2217                   typename allocator_traits<_Allocator>::size_type = 0,
2218                   _Hash                                            = _Hash(),
2219                   _Pred                                            = _Pred(),
2220                   _Allocator                                       = _Allocator())
2221    -> unordered_multimap<__iter_key_type<_InputIterator>,
2222                          __iter_mapped_type<_InputIterator>,
2223                          _Hash,
2224                          _Pred,
2225                          _Allocator>;
2226
2227#  if _LIBCPP_STD_VER >= 23
2228template <ranges::input_range _Range,
2229          class _Hash      = hash<__range_key_type<_Range>>,
2230          class _Pred      = equal_to<__range_key_type<_Range>>,
2231          class _Allocator = allocator<__range_to_alloc_type<_Range>>,
2232          class            = enable_if_t<!__is_allocator<_Hash>::value>,
2233          class            = enable_if_t<!is_integral<_Hash>::value>,
2234          class            = enable_if_t<!__is_allocator<_Pred>::value>,
2235          class            = enable_if_t<__is_allocator<_Allocator>::value>>
2236unordered_multimap(from_range_t,
2237                   _Range&&,
2238                   typename allocator_traits<_Allocator>::size_type = 0,
2239                   _Hash                                            = _Hash(),
2240                   _Pred                                            = _Pred(),
2241                   _Allocator                                       = _Allocator())
2242    -> unordered_multimap<__range_key_type<_Range>, __range_mapped_type<_Range>, _Hash, _Pred, _Allocator>;
2243#  endif
2244
2245template <class _Key,
2246          class _Tp,
2247          class _Hash      = hash<remove_const_t<_Key>>,
2248          class _Pred      = equal_to<remove_const_t<_Key>>,
2249          class _Allocator = allocator<pair<const _Key, _Tp>>,
2250          class            = enable_if_t<!__is_allocator<_Hash>::value>,
2251          class            = enable_if_t<!is_integral<_Hash>::value>,
2252          class            = enable_if_t<!__is_allocator<_Pred>::value>,
2253          class            = enable_if_t<__is_allocator<_Allocator>::value>>
2254unordered_multimap(initializer_list<pair<_Key, _Tp>>,
2255                   typename allocator_traits<_Allocator>::size_type = 0,
2256                   _Hash                                            = _Hash(),
2257                   _Pred                                            = _Pred(),
2258                   _Allocator                                       = _Allocator())
2259    -> unordered_multimap<remove_const_t<_Key>, _Tp, _Hash, _Pred, _Allocator>;
2260
2261template <class _InputIterator,
2262          class _Allocator,
2263          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2264          class = enable_if_t<__is_allocator<_Allocator>::value>>
2265unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
2266    -> unordered_multimap<__iter_key_type<_InputIterator>,
2267                          __iter_mapped_type<_InputIterator>,
2268                          hash<__iter_key_type<_InputIterator>>,
2269                          equal_to<__iter_key_type<_InputIterator>>,
2270                          _Allocator>;
2271
2272template <class _InputIterator,
2273          class _Allocator,
2274          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2275          class = enable_if_t<__is_allocator<_Allocator>::value>>
2276unordered_multimap(_InputIterator, _InputIterator, _Allocator)
2277    -> unordered_multimap<__iter_key_type<_InputIterator>,
2278                          __iter_mapped_type<_InputIterator>,
2279                          hash<__iter_key_type<_InputIterator>>,
2280                          equal_to<__iter_key_type<_InputIterator>>,
2281                          _Allocator>;
2282
2283template <class _InputIterator,
2284          class _Hash,
2285          class _Allocator,
2286          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2287          class = enable_if_t<!__is_allocator<_Hash>::value>,
2288          class = enable_if_t<!is_integral<_Hash>::value>,
2289          class = enable_if_t<__is_allocator<_Allocator>::value>>
2290unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
2291    -> unordered_multimap<__iter_key_type<_InputIterator>,
2292                          __iter_mapped_type<_InputIterator>,
2293                          _Hash,
2294                          equal_to<__iter_key_type<_InputIterator>>,
2295                          _Allocator>;
2296
2297#  if _LIBCPP_STD_VER >= 23
2298
2299template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2300unordered_multimap(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Allocator)
2301    -> unordered_multimap<__range_key_type<_Range>,
2302                          __range_mapped_type<_Range>,
2303                          hash<__range_key_type<_Range>>,
2304                          equal_to<__range_key_type<_Range>>,
2305                          _Allocator>;
2306
2307template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2308unordered_multimap(from_range_t, _Range&&, _Allocator)
2309    -> unordered_multimap<__range_key_type<_Range>,
2310                          __range_mapped_type<_Range>,
2311                          hash<__range_key_type<_Range>>,
2312                          equal_to<__range_key_type<_Range>>,
2313                          _Allocator>;
2314
2315template <ranges::input_range _Range,
2316          class _Hash,
2317          class _Allocator,
2318          class = enable_if_t<!__is_allocator<_Hash>::value>,
2319          class = enable_if_t<!is_integral<_Hash>::value>,
2320          class = enable_if_t<__is_allocator<_Allocator>::value>>
2321unordered_multimap(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
2322    -> unordered_multimap<__range_key_type<_Range>,
2323                          __range_mapped_type<_Range>,
2324                          _Hash,
2325                          equal_to<__range_key_type<_Range>>,
2326                          _Allocator>;
2327
2328#  endif
2329
2330template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2331unordered_multimap(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Allocator)
2332    -> unordered_multimap<remove_const_t<_Key>,
2333                          _Tp,
2334                          hash<remove_const_t<_Key>>,
2335                          equal_to<remove_const_t<_Key>>,
2336                          _Allocator>;
2337
2338template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2339unordered_multimap(initializer_list<pair<_Key, _Tp>>, _Allocator)
2340    -> unordered_multimap<remove_const_t<_Key>,
2341                          _Tp,
2342                          hash<remove_const_t<_Key>>,
2343                          equal_to<remove_const_t<_Key>>,
2344                          _Allocator>;
2345
2346template <class _Key,
2347          class _Tp,
2348          class _Hash,
2349          class _Allocator,
2350          class = enable_if_t<!__is_allocator<_Hash>::value>,
2351          class = enable_if_t<!is_integral<_Hash>::value>,
2352          class = enable_if_t<__is_allocator<_Allocator>::value>>
2353unordered_multimap(
2354    initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
2355    -> unordered_multimap<remove_const_t<_Key>, _Tp, _Hash, equal_to<remove_const_t<_Key>>, _Allocator>;
2356#endif
2357
2358template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2359unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2360    size_type __n, const hasher& __hf, const key_equal& __eql)
2361    : __table_(__hf, __eql) {
2362  __table_.__rehash_multi(__n);
2363}
2364
2365template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2366unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2367    size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
2368    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
2369  __table_.__rehash_multi(__n);
2370}
2371
2372template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2373template <class _InputIterator>
2374unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(_InputIterator __first, _InputIterator __last) {
2375  insert(__first, __last);
2376}
2377
2378template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2379template <class _InputIterator>
2380unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2381    _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const key_equal& __eql)
2382    : __table_(__hf, __eql) {
2383  __table_.__rehash_multi(__n);
2384  insert(__first, __last);
2385}
2386
2387template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2388template <class _InputIterator>
2389unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2390    _InputIterator __first,
2391    _InputIterator __last,
2392    size_type __n,
2393    const hasher& __hf,
2394    const key_equal& __eql,
2395    const allocator_type& __a)
2396    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
2397  __table_.__rehash_multi(__n);
2398  insert(__first, __last);
2399}
2400
2401template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2402inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(const allocator_type& __a)
2403    : __table_(typename __table::allocator_type(__a)) {}
2404
2405template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2406unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(const unordered_multimap& __u)
2407    : __table_(__u.__table_) {
2408  __table_.__rehash_multi(__u.bucket_count());
2409  insert(__u.begin(), __u.end());
2410}
2411
2412template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2413unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2414    const unordered_multimap& __u, const allocator_type& __a)
2415    : __table_(__u.__table_, typename __table::allocator_type(__a)) {
2416  __table_.__rehash_multi(__u.bucket_count());
2417  insert(__u.begin(), __u.end());
2418}
2419
2420#ifndef _LIBCPP_CXX03_LANG
2421
2422template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2423inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(unordered_multimap&& __u)
2424    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
2425    : __table_(std::move(__u.__table_)) {}
2426
2427template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2428unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2429    unordered_multimap&& __u, const allocator_type& __a)
2430    : __table_(std::move(__u.__table_), typename __table::allocator_type(__a)) {
2431  if (__a != __u.get_allocator()) {
2432    iterator __i = __u.begin();
2433    while (__u.size() != 0) {
2434      __table_.__insert_multi(__u.__table_.remove((__i++).__i_)->__get_value().__move());
2435    }
2436  }
2437}
2438
2439template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2440unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(initializer_list<value_type> __il) {
2441  insert(__il.begin(), __il.end());
2442}
2443
2444template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2445unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2446    initializer_list<value_type> __il, size_type __n, const hasher& __hf, const key_equal& __eql)
2447    : __table_(__hf, __eql) {
2448  __table_.__rehash_multi(__n);
2449  insert(__il.begin(), __il.end());
2450}
2451
2452template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2453unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2454    initializer_list<value_type> __il,
2455    size_type __n,
2456    const hasher& __hf,
2457    const key_equal& __eql,
2458    const allocator_type& __a)
2459    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
2460  __table_.__rehash_multi(__n);
2461  insert(__il.begin(), __il.end());
2462}
2463
2464template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2465inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>&
2466unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(unordered_multimap&& __u)
2467    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value) {
2468  __table_ = std::move(__u.__table_);
2469  return *this;
2470}
2471
2472template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2473inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>&
2474unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(initializer_list<value_type> __il) {
2475  __table_.__assign_multi(__il.begin(), __il.end());
2476  return *this;
2477}
2478
2479#endif // _LIBCPP_CXX03_LANG
2480
2481template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2482template <class _InputIterator>
2483inline void unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first, _InputIterator __last) {
2484  for (; __first != __last; ++__first)
2485    __table_.__insert_multi(*__first);
2486}
2487
2488template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2489inline _LIBCPP_HIDE_FROM_ABI void
2490swap(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
2491    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
2492  __x.swap(__y);
2493}
2494
2495#if _LIBCPP_STD_VER >= 20
2496template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc, class _Predicate>
2497inline _LIBCPP_HIDE_FROM_ABI typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::size_type
2498erase_if(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __c, _Predicate __pred) {
2499  return std::__libcpp_erase_if_container(__c, __pred);
2500}
2501#endif
2502
2503template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2504_LIBCPP_HIDE_FROM_ABI bool operator==(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
2505                                      const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
2506  if (__x.size() != __y.size())
2507    return false;
2508  typedef typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
2509  typedef pair<const_iterator, const_iterator> _EqRng;
2510  for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;) {
2511    _EqRng __xeq = __x.equal_range(__i->first);
2512    _EqRng __yeq = __y.equal_range(__i->first);
2513    if (std::distance(__xeq.first, __xeq.second) != std::distance(__yeq.first, __yeq.second) ||
2514        !std::is_permutation(__xeq.first, __xeq.second, __yeq.first))
2515      return false;
2516    __i = __xeq.second;
2517  }
2518  return true;
2519}
2520
2521#if _LIBCPP_STD_VER <= 17
2522
2523template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2524inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
2525                                             const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
2526  return !(__x == __y);
2527}
2528
2529#endif
2530
2531_LIBCPP_END_NAMESPACE_STD
2532
2533#if _LIBCPP_STD_VER >= 17
2534_LIBCPP_BEGIN_NAMESPACE_STD
2535namespace pmr {
2536template <class _KeyT, class _ValueT, class _HashT = std::hash<_KeyT>, class _PredT = std::equal_to<_KeyT>>
2537using unordered_map _LIBCPP_AVAILABILITY_PMR =
2538    std::unordered_map<_KeyT, _ValueT, _HashT, _PredT, polymorphic_allocator<std::pair<const _KeyT, _ValueT>>>;
2539
2540template <class _KeyT, class _ValueT, class _HashT = std::hash<_KeyT>, class _PredT = std::equal_to<_KeyT>>
2541using unordered_multimap _LIBCPP_AVAILABILITY_PMR =
2542    std::unordered_multimap<_KeyT, _ValueT, _HashT, _PredT, polymorphic_allocator<std::pair<const _KeyT, _ValueT>>>;
2543} // namespace pmr
2544_LIBCPP_END_NAMESPACE_STD
2545#endif
2546
2547#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
2548#  include <algorithm>
2549#  include <bit>
2550#  include <concepts>
2551#  include <cstdlib>
2552#  include <iterator>
2553#  include <type_traits>
2554#endif
2555
2556#endif // _LIBCPP_UNORDERED_MAP
2557